Gene Summary

Gene:SOS1; SOS Ras/Rac guanine nucleotide exchange factor 1
Aliases: GF1, HGF, NS4, GGF1, GINGF, SOS-1
Summary:This gene encodes a protein that is a guanine nucleotide exchange factor for RAS proteins, membrane proteins that bind guanine nucleotides and participate in signal transduction pathways. GTP binding activates and GTP hydrolysis inactivates RAS proteins. The product of this gene may regulate RAS proteins by facilitating the exchange of GTP for GDP. Mutations in this gene are associated with gingival fibromatosis 1 and Noonan syndrome type 4. [provided by RefSeq, Jul 2008]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:son of sevenless homolog 1
Source:NCBIAccessed: 01 September, 2019


What does this gene/protein do?
Show (25)
Pathways:What pathways are this gene/protein implicaed in?
Show (42)

Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 01 September 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Adolescents
  • Oligonucleotide Array Sequence Analysis
  • MicroRNAs
  • Lung Cancer
  • Antineoplastic Agents
  • Haematological Malignancies
  • Signal Transduction
  • Cancer Gene Expression Regulation
  • Intracellular Signaling Peptides and Proteins
  • Extracellular Signal-Regulated MAP Kinases
  • T-Lymphocyte Subsets
  • p120 GTPase Activating Protein
  • Cell Movement
  • Spinal Nerves
  • Mutation
  • Noonan Syndrome
  • ras Proteins
  • Gene Expression Profiling
  • Neoplasm Proteins
  • TNF
  • Mitogen-Activated Protein Kinase Kinases
  • Phosphorylation
  • Cell Proliferation
  • Phenotype
  • MAP Kinase Signaling System
  • rho GTP-Binding Proteins
  • Missense Mutation
  • Adenocarcinoma
  • Proto-Oncogene Proteins p21(ras)
  • DNA Sequence Analysis
  • Transfection
  • Genetic Predisposition
  • Proto-Oncogene Proteins
  • Neoplasm Invasiveness
  • Neurofibromatosis 1
  • Transduction
  • Synovitis, Pigmented Villonodular
  • Childhood Cancer
  • Chromosome 2
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Apoptosis
Tag cloud generated 01 September, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Entity Topic PubMed Papers
-SOS1 and Noonan Syndrome View Publications18
Noonan SyndromeSOS1 mutation in Noonan Syndrome
Noonan Syndrome is an autosamal dominant multi-system disorder, characterised by facial anomalies, short stature, developmental delay, cardiac abnormalities and other symptoms. The syndrome pre-disposes to myeloproliferative disorders ( mainly chronic myeolomonocytic leukemia / juvenile myelomonocytic leukemia and acute lymphoblastic leukemia), with reports of neuroblastoma, rhabdomyosarcoma and a wide range of other tumors.
View Publications18
Lung CancerSOS1 and Lung Cancer View Publications10
Haematological MalignanciesSOS1 and Haematological Malignancies View Publications3

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: SOS1 (cancer-related)

Zhang X, Liu N, Zhou M, et al.
DNA Nanorobot Delivers Antisense Oligonucleotides Silencing c-Met Gene Expression for Cancer Therapy.
J Biomed Nanotechnol. 2019; 15(9):1948-1959 [PubMed] Related Publications
Antisense oligonucleotides are considered to be a promising strategy for cancer therapy because of their high specificity and minimal side effects. They can bind specifically to mRNA silencing the expression of target genes. However, ssDNA cannot enter cells in large quantities, which limits its applications. Tetrahedral framework nucleic acids (tFNA) are considered to be optimal nanoscopic drug carriers because of their editability and biocompatibility. Most importantly, they can be modified with functional molecules. The over-expression of c-Met is associated with a wide variety of tumor occurrences, developments, drug resistance and prognoses. Activation of HGF/c-Met signaling pathways can promote cell migration and invasion in cancer. Therefore, blocking the expression of c-Met is a valid technique for cancer therapy. In this study, we used tFNA as carriers to deliver antisense oligonucleotides, which can bind to c-Met mRNA with high specificity and affinity, into cells resulting in the inhibition of c-Met expression for cancer therapy.

Matte I, Garde-Granger P, Bessette P, Piché A
Ascites from ovarian cancer patients stimulates MUC16 mucin expression and secretion in human peritoneal mesothelial cells through an Akt-dependent pathway.
BMC Cancer. 2019; 19(1):406 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: CA125 is a well-established ovarian cancer (OC) serum biomarker. The CA125 heavily glycosylated epitope is carried by the MUC16 mucin, a high molecular weight transmembrane mucin. Upon proteolytic cleavage, the extracellular domain of MUC16 is released from the cell surface into malignant ascites and blood vessels. Previous studies have shown that both tumor and surrounding mesothelial cells may express MUC16. Although little is known about the regulation of MUC16 expression in these cells, recent evidence suggest that inflammatory cytokines may stimulate MUC16 expression. Because malignant ascites is a pro-inflammatory environment, we investigated whether OC ascites stimulate the expression and release of MUC16 by human peritoneal mesothelial cells (HPMCs).
METHODS: HPMCs were isolated from peritoneal lavages of women operated for conditions other than cancer. MUC16 protein expression was determined by immunoblot, immunofluorescence or immunohistochemistry depending on the experiments. The release of MUC16 from the cell surface was measured using EIA and MUC16 mRNA expression by ddPCR.
RESULTS: We show that high-grade serous ascites from patients with OC (n = 5) enhance MUC16 expression in HPMCs. Malignant ascites, but not benign peritoneal fluids, stimulate the release of MUC16 in HPMCs in a dose-dependent manner, which is abrogated by heat inactivation. Moreover, we establish that ascites-induced MUC16 expression occurs at the post-transcriptional level and demonstrate that ascites-induced MUC16 expression is mediated, at least partially, through an Akt-dependent pathway. A cytokine array identified upregulation of several cytokines and chemokines in ascites that mediate MUC16 upregulation versus those that do not, including CCL7, CCL8, CCL16, CCL20, CXCL1, IL-6, IL-10, HGF and IL-1 R4. However, when individually tested, none of these factors affected MUC16 expression or secretion. Concentrations of CA125 in the serum of a given patient did not correlate with the ability of its corresponding ascites to stimulate MUC16 release in HPMCs.
CONCLUSIONS: Collectively, these data indicate that mesothelial cells are an important source of MUC16 in the context of ovarian cancer and malignant ascites is a strong modulator of MUC16 expression in HPMCs and uncover the Akt pathway as a driving factor for upregulation of MUC16. Factors in ascites associated with enhanced MUC16 expression and release remains to be identified.

Veenstra C, Karlsson E, Mirwani SM, et al.
The effects of PTPN2 loss on cell signalling and clinical outcome in relation to breast cancer subtype.
J Cancer Res Clin Oncol. 2019; 145(7):1845-1856 [PubMed] Free Access to Full Article Related Publications
PURPOSE: The protein tyrosine phosphatase PTPN2 dephosphorylates several tyrosine kinases in cancer-related signalling pathways and is thought to be a tumour suppressor. As PTPN2 is not frequently studied in breast cancer, we aimed to explore the role of PTPN2 and the effects of its loss in breast cancer.
METHODS: Protein expression and gene copy number of PTPN2 were analysed in a cohort of pre-menopausal breast cancer patients with immunohistochemistry and droplet digital PCR, respectively. PTPN2 was knocked down in three cell lines, representing different breast cancer subtypes, with siRNA transfection. Several proteins related to PTPN2 were analysed with Western blot.
RESULTS: Low PTPN2 protein expression was found in 50.2% of the tumours (110/219), gene copy loss in 15.4% (33/214). Low protein expression was associated with a higher relapse rate in patients with Luminal A and HER2-positive tumours, but not triple-negative tumours. In vitro studies further suggested a subtype-specific role of PTPN2. Knockdown of PTPN2 had no effect on the triple-negative cell line, whilst knockdown in MCF7 inhibited phosphorylation of Met and promoted that of Akt. Knockdown in SKBR3 led to increased Met phosphorylation and decreased Erk phosphorylation as well as EGF-mediated STAT3 activation.
CONCLUSION: We confirm previous studies showing that the PTPN2 protein is lost in half of the breast cancer cases and gene deletion occurs in 15-18% of the cases. Furthermore, the results suggest that the role of PTPN2 is subtype-related and should be further investigated to assess how this could affect breast cancer prognosis and treatment response.

Jaafari-Ashkvandi Z, Shirazi SY, Rezaeifard S, et al.
Cytotoxic Effects of Pistacia Atlantica (Baneh) Fruit Extract on Human KB Cancer Cell Line.
Acta Medica (Hradec Kralove). 2019; 62(1):30-34 [PubMed] Related Publications
Plants with anticancer properties are considered as cancer preventive and treatment sources, due to their some biological effects. Apoptosis induction and anti-proliferative effects of Baneh extract on various cancer cell lines have been reported. Hence, this study was designed to evaluate the cytotoxic effects of this fruit on KB and human gingival fibroblast cell lines (HGF). KB and HGF cells were treated with various concentrations of ethanolic Baneh extract and cisplatin as positive control. Cytotoxic activity and apoptosis induction were investigated using WST-1 and Annexin V assays. Data were analyzed using ANOVA and student's t-tests. IC50 after 24 and 48 hours treatment were respectively 2.6 and 1 mg/mL for KB cell line, and 1.5 and 1.6 mg/mL for HGF cell. During 48 hours Baneh extract induced apoptosis without significant necrosis, in a time- and dose-dependent manner. The induction of apoptosis in KB cells was significantly higher than HGF. It seems that ethanolic extract of Baneh contains compounds that can suppress KB cell growth through the induction of apoptosis. Within 48 hours, less cytotoxic effects were observed on normal fibroblast cells; therefore, it might be a potential anticancer agent.

Braun R, Ronquist S, Wangsa D, et al.
Single Chromosome Aneuploidy Induces Genome-Wide Perturbation of Nuclear Organization and Gene Expression.
Neoplasia. 2019; 21(4):401-412 [PubMed] Free Access to Full Article Related Publications
Chromosomal aneuploidy is a defining feature of carcinomas and results in tumor-entity specific genomic imbalances. For instance, most sporadic colorectal carcinomas carry extra copies of chromosome 7, an aneuploidy that emerges already in premalignant adenomas, and is maintained throughout tumor progression and in derived cell lines. A comprehensive understanding on how chromosomal aneuploidy affects nuclear organization and gene expression, i.e., the nucleome, remains elusive. We now analyzed a cell line established from healthy colon mucosa with a normal karyotype (46,XY) and its isogenic derived cell line that acquired an extra copy of chromosome 7 as its sole anomaly (47,XY,+7). We studied structure/function relationships consequent to aneuploidization using genome-wide chromosome conformation capture (Hi-C), RNA sequencing and protein profiling. The gain of chromosome 7 resulted in an increase of transcript levels of resident genes as well as genome-wide gene and protein expression changes. The Hi-C analysis showed that the extra copy of chromosome 7 is reflected in more interchromosomal contacts between the triploid chromosomes. Chromatin organization changes are observed genome-wide, as determined by changes in A/B compartmentalization and topologically associating domain (TAD) boundaries. Most notably, chromosome 4 shows a profound loss of chromatin organization, and chromosome 14 contains a large A/B compartment switch region, concurrent with resident gene expression changes. No changes to the nuclear position of the additional chromosome 7 territory were observed when measuring distances of chromosome painting probes by interphase FISH. Genome and protein data showed enrichment in signaling pathways crucial for malignant transformation, such as the HGF/MET-axis. We conclude that a specific chromosomal aneuploidy has profound impact on nuclear structure and function, both locally and genome-wide. Our study provides a benchmark for the analysis of cancer nucleomes with complex karyotypes.

Yu G, Wang Z, Zeng S, et al.
Paeoniflorin Inhibits Hepatocyte Growth Factor- (HGF-) Induced Migration and Invasion and Actin Rearrangement via Suppression of c-Met-Mediated RhoA/ROCK Signaling in Glioblastoma.
Biomed Res Int. 2019; 2019:9053295 [PubMed] Free Access to Full Article Related Publications
Paeoniflorin (PF), as one of the important valid natural compounds of the total glucosides of peony, has displayed a potential effect in cancer prevention and treatment. Aggressive migration and invasion, as an important process, can contribute to tumor progression through infiltrating the surround normal tissue. Actin cytoskeleton rearrangement plays a key role in cells migration and invasion, involving multiple signal pathways. HGF/c-Met signal, as an important couple of oncoprotein, has been demonstrated to regulate actin cytoskeleton rearrangement. In our study, we aim to explore whether paeoniflorin can inhibit migration and invasion and actin cytoskeleton rearrangement via regulation of HGF/c-Met/RhoA/ROCK signal. Various approaches were applied to demonstrate the mechanism of paeoniflorin-mediated anticancer effect, including cell wound healing assay, invasion assay, immunofluorescence staining and transfection, and western blotting. We observed that paeoniflorin inhibited HGF-induced migration and invasion and actin cytoskeleton rearrangement in glioblastoma cells. Furthermore, the inhibition of HGF-induced migration and invasion and actin cytoskeleton rearrangement involved c-Met-mediated RhoA/ROCK signaling in glioblastoma. Thus, our study proved that paeoniflorin could inhibit migration and invasion and actin cytoskeleton rearrangement through inhibition of HGF/c-Met/RhoA/ROCK signaling in glioblastoma, suggesting that paeoniflorin might be a candidate compound to treat glioblastoma.

Liu F, Cox CD, Chowdhury R, et al.
SPINT2 is hypermethylated in both IDH1 mutated and wild-type glioblastomas, and exerts tumor suppression via reduction of c-Met activation.
J Neurooncol. 2019; 142(3):423-434 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
PURPOSE: Both IDH1-mutated and wild-type gliomas abundantly display aberrant CpG island hypermethylation. However, the potential role of hypermethylation in promoting gliomas, especially the most aggressive form, glioblastoma (GBM), remains poorly understood.
METHODS: We analyzed RRBS-generated methylation profiles for 11 IDH1
RESULTS: We identified SPINT2 as a candidate tumor-suppressor gene within a group of CpG islands (designated G
CONCLUSIONS: We defined a previously under-recognized group of coordinately methylated CpG islands common to both IDH1

Zhan FB, Zhang XW, Feng SL, et al.
MicroRNA-206 Reduces Osteosarcoma Cell Malignancy
Yonsei Med J. 2019; 60(2):163-173 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
PURPOSE: This study was undertaken to explore how miR-206 represses osteosarcoma (OS) development.
MATERIALS AND METHODS: Expression levels of miR-206, PAX3, and MET mRNA were explored in paired OS and adjacent tissue specimens. A patient-derived OS cell line was established. miR-206 overexpression and knockdown were achieved by lentiviral transduction. PAX3 and MET overexpression were achieved by plasmid transfection. Treatment with hepatocyte growth factor (HGF) was utilized to activate c-Met receptor. Associations between miR-206 and PAX3 or MET mRNA in OS cells were verified by AGO2-RNA immunoprecipitation assay and miRNA pulldown assay. OS cell malignancy was evaluated
RESULTS: Expression levels of miR-206 were significantly decreased in OS tissue specimens, compared to adjacent counterparts, and were inversely correlated with expression of PAX3 and MET mRNA. miR-206 directly interacted with PAX3 and MET mRNA in OS cells. miR-206 overexpression significantly reduced PAX3 and MET gene expression in OS cells
CONCLUSION: miR-206 reduces OS cell malignancy

Leonetti E, Gesualdi L, Scheri KC, et al.
c-Src Recruitment is Involved in c-MET-Mediated Malignant Behaviour of NT2D1 Non-Seminoma Cells.
Int J Mol Sci. 2019; 20(2) [PubMed] Article available free on PMC after 01/05/2020 Related Publications

Giannoni P, Fais F, Cutrona G, Totero D
Hepatocyte Growth Factor: A Microenvironmental Resource for Leukemic Cell Growth.
Int J Mol Sci. 2019; 20(2) [PubMed] Article available free on PMC after 01/05/2020 Related Publications
Chronic lymphocytic leukemia (CLL) is characterized by the progressive expansion of B lymphocytes CD5+/CD23+ in peripheral blood, lymph-nodes, and bone marrow. The pivotal role played by the microenvironment in disease pathogenesis has become increasingly clear. We demonstrated that bone marrow stromal cells and trabecular bone cells sustain survival of leukemic B cells through the production of hepatocyte growth factor (HGF). Indeed the trans-membrane kinase receptor for HGF, c-MET, is expressed on CLL cells and STAT3 TYR

Martins-Costa MC, Lindsey SC, Cunha LL, et al.
A pioneering RET genetic screening study in the State of Ceará, Brazil, evaluating patients with medullary thyroid cancer and at-risk relatives: experience with 247 individuals.
Arch Endocrinol Metab. 2018; 62(6):623-635 [PubMed] Related Publications
OBJECTIVE: Initial diagnosis of medullary thyroid carcinoma (MTC) is frequently associated with advanced stages and a poor prognosis. Thus, the need for earlier diagnoses and detection in relatives at risk for the disease has led to increased use of RET genetic screening.
SUBJECTS AND METHODS: We performed RET screening in 247 subjects who were referred to the Brazilian Research Consortium for Multiple Endocrine Neoplasia (BRASMEN) Center in the State of Ceará. Direct genetic sequencing was used to analyze exons 8, 10, 11, and 13-16 in MTC index cases and specific exons in at risk relatives. Afterward, clinical follow-up was offered to all the patients with MTC and their affected relatives.
RESULTS: RET screening was performed in 60 MTC index patients and 187 at-risk family members. At the initial clinical assessment of the index patients, 54 (90%) were diagnosed with apparently sporadic disease and 6 (10%) diagnosed with hereditary disease. After RET screening, we found that 31 (52%) index patients had sporadic disease, and 29 (48%) had hereditary disease. Regarding at-risk relatives, 73/187 were mutation carriers. Mutations in RET codon 804 and the rare p.M918V mutation were the most prevalent.
CONCLUSIONS: Performing RET screening in Ceará allowed us to identify a different mutation profile in this region compared with other areas. RET screening also enabled the diagnosis of a significant number of hereditary MTC patients who were initially classified as sporadic disease patients and benefited their relatives, who were unaware of the risks and the consequences of bearing a RET mutation.

Naito A, Sakao S, Lang IM, et al.
Endothelial cells from pulmonary endarterectomy specimens possess a high angiogenic potential and express high levels of hepatocyte growth factor.
BMC Pulm Med. 2018; 18(1):197 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
BACKGROUND: Impaired angiogenesis is assumed to be an important factor in the development of chronic thromboembolic pulmonary hypertension (CTEPH). However, the role of endothelial cells (ECs) in CTEPH remains unclear. The aim of this study was to investigate the angiogenic potential of ECs from pulmonary endarterectomy (PEA) specimens.
METHODS: We isolated ECs from PEA specimens (CTEPH-ECs) and control EC lines from the intact pulmonary arteries of patients with peripheral lung cancers, using a MACS system. These cells were analyzed in vitro including PCR-array analysis, and the PEA specimens were analyzed with immunohistochemistry. Additionally, the serum HGF levels were determined in CTEPH patients.
RESULTS: A three-dimensional culture assay revealed that CTEPH-ECs were highly angiogenic. An angiogenesis-focused gene PCR array revealed a high expression of hepatocyte growth factor (HGF) in CTEPH-ECs. The high expression of HGF was also confirmed in the supernatant extracted from PEA specimens. The immunohistochemical analysis showed expression of HGF on the surface of the thrombus vessels. The serum HGF levels in CTEPH patients were higher than those in pulmonary thromboembolism survivors.
CONCLUSION: Our study suggests that there are ECs with pro-angiogenetic character and high expression of HGF in PEA specimens. It remains unknown how these results are attributable to the etiology. However, further investigation focused on the HGF pathway may provide novel diagnostic and therapeutic tools for patients with CTEPH.

Du M, Wang J, Chen H, et al.
MicroRNA‑200a suppresses migration and invasion and enhances the radiosensitivity of NSCLC cells by inhibiting the HGF/c‑Met signaling pathway.
Oncol Rep. 2019; 41(3):1497-1508 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
Hepatocyte growth factor (HGF), an activator of the c‑Met signaling pathway, is involved in tumor invasiveness, metastasis and radiotherapy resistance. In the present study, a novel HGF regulatory pathway in lung cancer involving micro-RNAs (miRNAs/miR) is described. Immunohistochemical staining and western blot analyses demonstrated that HGF was upregulated and associated with miR‑200a downregulation in non‑small cell lung cancer (NSCLC) samples compared with normal lung tissues. The association between HGF and miR‑200a was associated with the degree of tumor malignancy and cell migration and invasion. miR‑200a negatively regulated HGF expression by targeting the 3'‑untranslated region of the HGF mRNA. miR‑200a overexpression induced HGF downregulation, decreased NSCLC cell migration and invasion, promoted apoptosis, and decreased cell survival in A549 and H1299 cells in response to ionizing radiation. The present results revealed a previously uncharacterized role of miRNA‑200a in regulating tumor malignancy and radiosensitivity by suppressing HGF expression, a key factor in the HGF/c‑Met pathway.

Modica C, Tortarolo D, Comoglio PM, et al.
MET/HGF Co-Targeting in Pancreatic Cancer: A Tool to Provide Insight into the Tumor/Stroma Crosstalk.
Int J Mol Sci. 2018; 19(12) [PubMed] Article available free on PMC after 01/05/2020 Related Publications
The 'onco-receptor' MET (Hepatocyte Growth Factor Receptor) is involved in the activation of the invasive growth program that is essential during embryonic development and critical for wound healing and organ regeneration during adult life. When aberrantly activated, MET and its stroma-secreted ligand HGF (Hepatocyte Growth Factor) concur to tumor onset, progression, and metastasis in solid tumors, thus representing a relevant target for cancer precision medicine. In the vast majority of tumors, wild-type

Lee JC, Koh SA, Lee KH, Kim JR
BAG3 contributes to HGF-mediated cell proliferation, migration, and invasion via the Egr1 pathway in gastric cancer.
Tumori. 2019; 105(1):63-75 [PubMed] Related Publications
INTRODUCTION:: Bcl2-associated athanogene 3 (BAG3) is elevated in several types of cancers. However, the role of BAG3 in progression of gastric cancer is unknown. Therefore, the present study aims to find out the role of BAG3 in hepatocyte growth factor (HGF)-mediated tumor progression and the molecular mechanisms by which HGF regulates BAG3 expression.
METHODS:: BAG3 mRNA and protein were measured using reverse transcription polymerase chain reaction and Western blot in the 2 human gastric cancer cell lines, NUGC3 and MKN28, treated with or without HGF. The effects of BAG3 knockdown on cell proliferation, cell invasion, and apoptosis were analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the in vitro 2-chamber invasion assay, and flow cytometry in BAG3 short hairpin RNA (shRNA)-transfected cells and control cells. The signaling pathways involved in BAG3 that are regulated by HGF were analyzed. The chromatin immunoprecipitation assay was used to determine binding of Egr1 to the BAG3 promoter.
RESULTS:: BAG3 mRNA and protein levels were increased following treatment with HGF. HGF-mediated BAG3 upregulation increased cell proliferation and cell invasion; however, it decreased apoptosis. HGF-mediated BAG3 upregulation is regulated by an ERK and Egr1-dependent pathway. BAG3 may have an important role in HGF-mediated cell proliferation and metastasis in gastric cancer through an ERK and Egr1-dependent pathway.
CONCLUSION:: This pathway may provide novel therapeutic targets and provide information for further identification of other targets of therapeutic significance in gastric cancer.

Basak P, Chatterjee S, Bhat V, et al.
Long Non-Coding RNA H19 Acts as an Estrogen Receptor Modulator that is Required for Endocrine Therapy Resistance in ER+ Breast Cancer Cells.
Cell Physiol Biochem. 2018; 51(4):1518-1532 [PubMed] Related Publications
BACKGROUND/AIMS: Blocking estrogen signaling with endocrine therapies (Tamoxifen or Fulverstrant) is an effective treatment for Estrogen Receptor-α positive (ER+) breast cancer tumours. Unfortunately, development of endocrine therapy resistance (ETR) is a frequent event resulting in disease relapse and decreased overall patient survival. The long noncoding RNA, H19, was previously shown to play a significant role in estrogen-induced proliferation of both normal and malignant ER+ breast epithelial cells. We hypothesized that H19 expression is also important for the proliferation and survival of ETR cells.
METHODS: Here we utilized established ETR cell models; the Tamoxifen (Tam)-resistant LCC2 and the Fulvestrant and Tam cross-resistant LCC9 cells. Gain and loss of H19 function were achieved through lentiviral transduction as well as pharmacological inhibitors of the Notch and c-Met receptor signaling pathways. The effects of altered H19 expression on cell viability and ETR were assessed using three-dimensional (3D) organoid cultures and 2D co-cultures with low passage tumour-associated fbroblasts (TAFs).
RESULTS: Here we report that treating ETR cells with Tam or Fulvestrant increases H19 expression and that it's decreased expression overcomes resistance to Tam and Fulvestrant in these cells. Interestingly, H19 expression is regulated by Notch and HGF signaling in the ETR cells and pharmacological inhibitors of Notch and c-MET signaling together significantly reverse resistance to Tam and Fulvestrant in an H19-dependent manner in these cells. Lastly, we demonstrate that H19 regulates ERα expression at the transcript and protein levels in the ETR cells and that H19 protects ERα against Fulvestrant-mediated downregulation of ERα protein. We also observed that blocking Notch and the c-MET receptor signaling also overcomes Fulvestrant and Tam resistance in 3D organoid cultures by decreasing ERα and H19 expression in the ETR cells.
CONCLUSION: In endocrine therapy resistant breast cancer cells Fulvestrant is ineffective in decreasing ERα levels. Our data suggest that in the ETR cells, H19 expression acts as an ER modulator and that its levels and subsequently ERα levels can be substantially decreased by blocking Notch and c-MET receptor signaling. Consequently, treating ETR cells with these pharmacological inhibitors helps overcome resistance to Fulvestrant and Tamoxifen.

Karachaliou N, Cardona AF, Bracht JWP, et al.
Integrin-linked kinase (ILK) and src homology 2 domain-containing phosphatase 2 (SHP2): Novel targets in EGFR-mutation positive non-small cell lung cancer (NSCLC).
EBioMedicine. 2019; 39:207-214 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
BACKGROUND: The activation of multiple signaling pathways jeopardizes the clinical efficacy of EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutation positive non-small cell lung cancer (NSCLC). Integrin-linked kinase (ILK) regulates the interactions between tumor cells and extracellular environment to activate signaling pathways and promote cell proliferation, migration, and epithelial-mesenchymal transition. Src homology 2 domain-containing phosphatase 2 (SHP2) is essential for receptor tyrosine kinase signaling and mitogen-activated protein kinase (MAPK) pathway activation.
METHODS: We analyzed tumor ILK, β-receptor subunit glycoprotein 130 (gp130), SHP2, and stromal hepatocyte growth factor (HGF) and interleukin-6 (IL-6) mRNA expression in baseline tumor specimens of advanced EGFR-mutation positive NSCLC patients treated with EGFR TKIs.
RESULTS: ILK, when highly expressed, was an independent poor prognostic factor for the progression-free survival of the patients, both in the univariate (hazard ratio [HR for disease progression, 2.49; 95% CI, 1.37-4.52; P = .0020]) and in the multivariate (HR 3.74; 95% CI, 1.33-10.56; P = .0126) Cox regression model. Patients with high SHP2 expression had an almost 13-month shorter progression-free survival (P = .0094) and an 18-month shorter overall survival (P = .0182) in comparison to those with low SHP2 mRNA expression.
INTERPRETATION: The levels of ILK and SHP2 could be predictive for upfront combinatory therapy of EGFR TKIs plus SHP2 or ILK inhibitors. FUND: A grant from La Caixa Foundation, an Instituto de Salud Carlos III grant (RESPONSE, PIE16/00011), an Instituto de Salud Carlos III grant (PI14/01678), a Marie Skłodowska-Curie Innovative Training Networks European Grant (ELBA No 765492) and a Spanish Association Against Cancer (AECC) grant (PROYE18012ROSE).

Lee G, Jeong YS, Kim DW, et al.
Clinical significance of APOB inactivation in hepatocellular carcinoma.
Exp Mol Med. 2018; 50(11):147 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
Recent findings from The Cancer Genome Atlas project have provided a comprehensive map of genomic alterations that occur in hepatocellular carcinoma (HCC), including unexpected mutations in apolipoprotein B (APOB). We aimed to determine the clinical significance of this non-oncogenetic mutation in HCC. An Apob gene signature was derived from genes that differed between control mice and mice treated with siRNA specific for Apob (1.5-fold difference; P < 0.005). Human gene expression data were collected from four independent HCC cohorts (n = 941). A prediction model was constructed using Bayesian compound covariate prediction, and the robustness of the APOB gene signature was validated in HCC cohorts. The correlation of the APOB signature with previously validated gene signatures was performed, and network analysis was conducted using ingenuity pathway analysis. APOB inactivation was associated with poor prognosis when the APOB gene signature was applied in all human HCC cohorts. Poor prognosis with APOB inactivation was consistently observed through cross-validation with previously reported gene signatures (NCIP A, HS, high-recurrence SNUR, and high RS subtypes). Knowledge-based gene network analysis using genes that differed between low-APOB and high-APOB groups in all four cohorts revealed that low-APOB activity was associated with upregulation of oncogenic and metastatic regulators, such as HGF, MTIF, ERBB2, FOXM1, and CD44, and inhibition of tumor suppressors, such as TP53 and PTEN. In conclusion, APOB inactivation is associated with poor outcome in patients with HCC, and APOB may play a role in regulating multiple genes involved in HCC development.

Schmidt KM, Dietrich P, Hackl C, et al.
Inhibition of mTORC2/RICTOR Impairs Melanoma Hepatic Metastasis.
Neoplasia. 2018; 20(12):1198-1208 [PubMed] Article available free on PMC after 01/05/2020 Related Publications
Mammalian target of rapamycin complex 2 (mTORC2) with its pivotal component rapamycin-insensitive companion of mTOR (RICTOR) is the major regulator of AKT phosphorylation and is increasingly implicated in tumor growth and progression. In cutaneous melanoma, an extremely aggressive and highly metastatic disease, RICTOR overexpression is involved in tumor development and invasiveness. Therefore, we investigated the impact of RICTOR inhibition in melanoma cells in vitro and in vivo with special emphasis on hepatic metastasis. Moreover, our study focused on the interaction of tumor cells and hepatic stellate cells (HSC) which play a crucial role in the hepatic microenvironment. In silico analysis revealed increased RICTOR expression in melanoma cells and tissues and indicated higher expression in advanced melanoma stages and metastases. In vitro, transient RICTOR knock-down via siRNA caused a significant reduction of tumor cell motility. Using a syngeneic murine splenic injection model, a significant decrease in liver metastasis burden was detected in vivo. Moreover, stimulation of melanoma cells with conditioned medium (CM) from activated HSC or hepatocyte growth factor (HGF) led to a significant induction of AKT phosphorylation and tumor cell motility. Blocking of RICTOR expression in cancer cells diminished constitutive and HGF-induced AKT phosphorylation as well as cell motility. Interestingly, RICTOR blockade also led to an abrogation of CM-induced effects on AKT phosphorylation and motility in melanoma cells. In conclusion, these results provide first evidence for a critical role of mTORC2/RICTOR in melanoma liver metastasis via cancer cell/HSC interactions.

Zhang H, Feng Q, Chen WD, Wang YD
HGF/c-MET: A Promising Therapeutic Target in the Digestive System Cancers.
Int J Mol Sci. 2018; 19(11) [PubMed] Article available free on PMC after 01/05/2020 Related Publications
The HGF/c-MET pathway is active in the development of digestive system cancers, indicating that inhibition of HGF/c-MET signaling may have therapeutic potential. Various HGF/c-MET signaling inhibitors, mainly c-MET inhibitors, have been tested in clinical trials. The observed efficacy and adverse events of some c-MET inhibitors were not very suitable for treating digestive system cancers. The development of new HGF/c-MET inhibitors in preclinical studies may bring promising treatments and synergistic combination (traditional anticancer drugs and c-MET inhibitors) strategies provided anacceptable safety and tolerability. Insights into miRNA biology and miRNA therapeutics have made miRNAs attractive tools to inhibit HGF/c-MET signaling. Recent reports show that several microRNAs participate in inhibiting HGF/c-MET signaling networks through antagonizing c-MET or HGF in digestive system cancers, and the miRNAs-HGF/c-MET axis plays crucial and novel roles for cancer treatment. In the current review, we will discuss recent findings about inhibitors of HGF/c-MET signaling in treating digestive system cancers, and how miRNAs regulate digestive system cancers via mediating HGF/c-MET pathway.

Gehlhausen JR, Hawley E, Wahle BM, et al.
A proteasome-resistant fragment of NIK mediates oncogenic NF-κB signaling in schwannomas.
Hum Mol Genet. 2019; 28(4):572-583 [PubMed] Article available free on PMC after 15/02/2020 Related Publications
Schwannomas are common, highly morbid and medically untreatable tumors that can arise in patients with germ line as well as somatic mutations in neurofibromatosis type 2 (NF2). These mutations most commonly result in the loss of function of the NF2-encoded protein, Merlin. Little is known about how Merlin functions endogenously as a tumor suppressor and how its loss leads to oncogenic transformation in Schwann cells (SCs). Here, we identify nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-inducing kinase (NIK) as a potential drug target driving NF-κB signaling and Merlin-deficient schwannoma genesis. Using a genomic approach to profile aberrant tumor signaling pathways, we describe multiple upregulated NF-κB signaling elements in human and murine schwannomas, leading us to identify a caspase-cleaved, proteasome-resistant NIK kinase domain fragment that amplifies pathogenic NF-κB signaling. Lentiviral-mediated transduction of this NIK fragment into normal SCs promotes proliferation, survival, and adhesion while inducing schwannoma formation in a novel in vivo orthotopic transplant model. Furthermore, we describe an NF-κB-potentiated hepatocyte growth factor (HGF) to MET proto-oncogene receptor tyrosine kinase (c-Met) autocrine feed-forward loop promoting SC proliferation. These innovative studies identify a novel signaling axis underlying schwannoma formation, revealing new and potentially druggable schwannoma vulnerabilities with future therapeutic potential.

Li H, Meng X, Zhang D, et al.
Ginkgolic acid suppresses the invasion of HepG2 cells via downregulation of HGF/c‑Met signaling.
Oncol Rep. 2019; 41(1):369-376 [PubMed] Related Publications
Liver cancer is one of the most devastating types of cancer worldwide. Despite years of improvements in treatment, the prognosis of patients with this type of malignancy remains poor due to frequent recurrence and metastasis after surgical resection. Ginkgolic acid (GA) is a botanical drug extracted from the seed coat of Ginkgo biloba L. that possesses a wide range of bioactive properties. However, to the best of our knowledge, whether GA can inhibit the invasion of liver cancer cells and the underlying mechanisms remains unknown. The aim of the present study was to investigate the effects of GA on the migration and invasion abilities of liver cancer cells and the underlying molecular mechanism. The results revealed that GA suppressed the migration and invasion abilities of HepG2 cells. In addition, GA treatment inhibited the expression of invasion‑related molecules (MMP‑2 and MMP‑9) and prevented the epithelial‑mesenchymal transition (EMT) of HepG2 cells. Further experiments revealed that GA‑reduced hepatocyte growth factor (HGF) production and suppressed c‑Met phosphorylation may be the underlying mechanisms. Exogenous recombinant HGF supplementation improved the cell invasion ability impaired by GA. Moreover, the in vivo experiment revealed that GA inhibited the tumor growth of liver cancer and prevented EMT. Collectively, these data indicated that GA effectively suppressed the invasion and EMT of HepG2 cells via downregulation of HGF/c‑Met signaling, thus GA may serve as a novel chemotherapeutic agent for the treatment of HCC.

Maruschke M, Koczan D, Ziems B, Hakenberg OW
Copy Number Alterations with Prognostic Potential in Clear Cell Renal Cell Carcinoma.
Urol Int. 2018; 101(4):417-424 [PubMed] Related Publications
OBJECTIVES: To detect chromosomal aberrations in a genome-wide manner with potential value for prognosis in groups of patients with different histopathological grading in clear cell renal carcinoma (ccRCC).
MATERIAL AND METHODS: We performed a copy number alteration analysis using the Affymetrix platform and SNP 6.0 mapping arrays with samples from 48 ccRCC-patients. The data analysis was done using 3 different Software Platforms: Affymetrix Genotyping Console (version and 2 open-source packages for validation: PennCNV and PICNIC.
RESULTS: Consistent changes were found to divide the tumors into 4 groups: first group showed typical losses on 3p, second group losses on 3p plus gains on 5q, third group gains on chromosome 7 plus losses on chromosome 8; fourth group did not show any major changes. We selected the affected genes with the highest consistency and identified 13 different genes mapping in the SNP 6.0 results and Kyoto Encyclopedia of Genes and Genomes. Remarkable for further consideration were the phosphatidylinositol 3-kinase pathway, BRAF, MET, EGLN1; growth factors, for example, HGF, PGF and TGFB2.
CONCLUSION: A multimodal approach with a well-defined workflow for detecting genomic aberrations by using array technologies and comparing the findings with different comprehensive databases may provide insights into functional tumor processes and help to identify potential new targets for more individualized future treatment.

García-Vilas JA, Medina MÁ
Updates on the hepatocyte growth factor/c-Met axis in hepatocellular carcinoma and its therapeutic implications.
World J Gastroenterol. 2018; 24(33):3695-3708 [PubMed] Article available free on PMC after 15/02/2020 Related Publications
Hepatocellular carcinoma (HCC) is the fifth most common cancer and is the second leading cause of cancer death. Since the diagnosis of HCC is difficult, in many cases patients with HCC are diagnosed advanced stage of development. Hepatocyte growth factor (HGF)/c-mesenchymal-epithelial transition receptor (c-Met) axis is a key signaling pathway in HCC, either via canonical or non-canonical pathways. Available treatments against HCC based upon HGF/c-Met inhibition can increase patient lifespan, but do not reach the expected therapeutic benefits. In HCC, c-Met monomers can bind other receptor monomers, activating several noncanonical signaling pathways, leading to increased cell proliferation, invasion, motility, and drug resistance. All of these processes are enhanced by the tumor microenvironment, with stromal cells contributing to boost tumor progression through oxidative stress, angiogenesis, lymphangiogenesis, inflammation, and fibrosis. Novel treatments against HCC are being explored to modulate other targets such as microRNAs, methyltransferases, and acetyltransferases, which are all involved in the regulation of gene expression in cancer. This review compiles basic knowledge regarding signaling pathways in HCC, and compounds already used or showing potential to be used in clinical trials.

Gnatenko DA, Kopantzev EP, Sverdlov ED
Variable Effects of Growth Factors on Developmental Gene Expression in Pancreatic Cancer Cells.
Dokl Biochem Biophys. 2018; 481(1):217-218 [PubMed] Related Publications
Stimulation of BxPC-3, Panc-1, and MIA PaCA-2 pancreatic cancer cells with EGF, HGF, FGF-1, FGF-2, FGF-7, and FGF-10 growth factors caused changes in the expression of master genes regulating pancreatic development (SOX9, HNF3b, GATA-4, GATA-6, and HES1). This, in turn, caused changes in the expression profile of important transcription factors, embryonic development regulators. It was also found that the master genes belonging to the same family may cause opposite effects (suppression or enhancement of expression of a particular transcriptional regulator) in the same cell line.

Duggimpudi S, Kloetgen A, Maney SK, et al.
Transcriptome-wide analysis uncovers the targets of the RNA-binding protein MSI2 and effects of MSI2's RNA-binding activity on IL-6 signaling.
J Biol Chem. 2018; 293(40):15359-15369 [PubMed] Article available free on PMC after 05/10/2019 Related Publications
The RNA-binding protein Musashi 2 (MSI2) has emerged as an important regulator in cancer initiation, progression, and drug resistance. Translocations and deregulation of the

Aliebrahimi S, Kouhsari SM, Arab SS, et al.
Phytochemicals, withaferin A and carnosol, overcome pancreatic cancer stem cells as c-Met inhibitors.
Biomed Pharmacother. 2018; 106:1527-1536 [PubMed] Related Publications
Receptor tyrosine kinases (RTKs) are pharmaceutically attractive targets due to their fundamental role in tumor formation. The hallmark of pancreatic cancer is its high mortality rate attributed to the existence of cancer stem cell (CSC) subpopulations which result in therapy resistance and recurrence. c-Met is a known pancreatic CSC marker that belongs to the family of RTKs. To surmount the hurdles related to ligand-independent c-Met activation, we aimed to elucidate the inhibitory mechanisms of withaferin A (WA) and carnosol (CA) as two hit phytochemicals against c-Met kinase domain. Both tested compounds attenuated HGF-mediated proliferation across various established c-Met

Li W, Xiong X, Abdalla A, et al.
HGF-induced formation of the MET-AXL-ELMO2-DOCK180 complex promotes RAC1 activation, receptor clustering, and cancer cell migration and invasion.
J Biol Chem. 2018; 293(40):15397-15418 [PubMed] Article available free on PMC after 05/10/2019 Related Publications

Cheng J, Wu LM, Deng XS, et al.
MicroRNA-449a suppresses hepatocellular carcinoma cell growth via G1 phase arrest and the HGF/MET c-Met pathway.
Hepatobiliary Pancreat Dis Int. 2018; 17(4):336-344 [PubMed] Related Publications
BACKGROUND: Accumulating evidence demonstrates that microRNAs (miRNAs) play essential roles in tumorigenesis and cancer progression of hepatocellular carcinoma (HCC). Average targets of a miRNA were more than 100. And one miRNA may act in tumor via regulating several targets. The present study aimed to explore more potential targets of miR-449a by proteomics technology and further uncover the role of miR-449a in HCC tumorigenesis.
METHODS: Technologies such as iTRAQ-based quantitative proteomic were used to investigate the effect of miR-449a on HCC. The expression of c-Met and miR-449a was detected by qRT-PCR in HCC samples. Gain- and loss-of-function experiments were performed to identify the function and potential target of miR-449a in HCC cells.
RESULTS: In HCC, miR-449a was significantly downregulated, while c-Met was upregulated concurrently. Quantitative proteomics and luciferase reporter assay identified c-Met as a direct target of miR-449a. Moreover, miR-449a inhibited HCC growth not only by targeting CDK6 but also by suppressing c-Met/Ras/Raf/ERK signaling pathway. Furthermore, the inhibition of c-Met expression with a specific siRNA significantly inhibited cells growth and deregulated the ERK pathway in HCC.
CONCLUSION: The tumor suppressor miR-449a suppresses HCC tumorigenesis by repressing the c-Met/ERK pathway.

Breunig C, Erdem N, Bott A, et al.
TGFβ1 regulates HGF-induced cell migration and hepatocyte growth factor receptor MET expression via C-ets-1 and miR-128-3p in basal-like breast cancer.
Mol Oncol. 2018; 12(9):1447-1463 [PubMed] Article available free on PMC after 05/10/2019 Related Publications
Breast cancer is the most common cancer in women worldwide. The tumor microenvironment contributes to tumor progression by inducing cell dissemination from the primary tumor and metastasis. TGFβ signaling is involved in breast cancer progression and is specifically elevated during metastatic transformation in aggressive breast cancer. In this study, we performed genomewide correlation analysis of TGFBR2 expression in a panel of 51 breast cancer cell lines and identified that MET is coregulated with TGFBR2. This correlation was confirmed at the protein level in breast cancer cell lines and human tumor tissues. Flow cytometric analysis of luminal and basal-like breast cancer cell lines and examination of 801 tumor specimens from a prospective cohort of breast cancer patients using reverse phase protein arrays revealed that expression of TGFBR2 and MET is increased in basal-like breast cancer cell lines, as well as in triple-negative breast cancer tumor tissues, compared to other subtypes. Using real-time cell analysis technology, we demonstrated that TGFβ1 triggered hepatocyte growth factor (HGF)-induced and MET-dependent migration in vitro. Bioinformatic analysis predicted that TGFβ1 induces expression of C-ets-1 as a candidate transcription factor regulating MET expression. Indeed, TGFβ1-induced expression of ETS1 and breast cancer cell migration was blocked by knockdown of ETS1. Further, we identified that MET is a direct target of miR-128-3p and that this miRNA is negatively regulated by TGFβ1. Overexpression of miR-128-3p reduced MET expression and abrogated HGF-induced cell migration of invasive breast cancer cells. In conclusion, we have identified that TGFβ1 regulates HGF-induced and MET-mediated cell migration, through positive regulation of C-ets-1 and negative regulation of miR-128-3p expression in basal-like breast cancer cell lines and in triple-negative breast cancer tissue.

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