Research IndicatorsGraph generated 16 March 2017 using data from PubMed using criteria.
Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic. Tag cloud generated 16 March, 2017 using data from PubMed, MeSH and CancerIndex
Specific Cancers (2)
Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.
Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).
OMIM, Johns Hopkin University
Referenced article focusing on the relationship between phenotype and genotype.
International Cancer Genome Consortium.
Summary of gene and mutations by cancer type from ICGC
Cancer Genome Anatomy Project, NCI
COSMIC, Sanger Institute
Somatic mutation information and related details
GEO Profiles, NCBI
Search the gene expression profiles from curated DataSets in the Gene Expression Omnibus (GEO) repository.
Latest Publications: LATS1 (cancer-related)
BACKGROUND: Osteosarcoma is the most common bone malignancy in children and adolescents, and 20%-30% of the patients suffer from poor prognosis because of individual chemoresistance. The Hippo/yes-associated protein (YAP) signaling pathway has been shown to play a role in tumor chemoresistance, but no previous report has focused on its involvement in osteosarcoma chemoresistance. This study aimed to investigate the role of the Hippo/YAP signaling pathway in osteosarcoma chemoresistance and to determine potential treatment targets.
METHODS: Using the Cell Titer-Glo Luminescent cell viability assay and flow cytometry analysis, we determined the proliferation and chemosensitivity of YAP-overexpressing and YAP-knockdown osteosarcoma cells. In addition, using western blotting and the real-time polymerase chain reaction technique, we investigated the alteration of the Hippo/YAP signaling pathway in osteosarcoma cells treated with chemotherapeutic agents.
RESULTS: Mammalian sterile 20-like kinase 1 (MST1) degradation was increased, and large tumor suppressor kinase 1/2 (LATS1/2) total protein levels were decreased by methotrexate and doxorubicin, which increased activation and nuclear translocation of YAP. Moreover, YAP increased the proliferation and chemoresistance of MG63 cells.
CONCLUSIONS: The Hippo/YAP signaling pathway plays a role in osteosarcoma chemoresistance, and YAP is a potential target for reducing chemoresistance.
Bonilla X, Parmentier L, King B, et al.Genomic analysis identifies new drivers and progression pathways in skin basal cell carcinoma.
Nat Genet. 2016; 48(4):398-406 [PubMed
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Basal cell carcinoma (BCC) of the skin is the most common malignant neoplasm in humans. BCC is primarily driven by the Sonic Hedgehog (Hh) pathway. However, its phenotypic variation remains unexplained. Our genetic profiling of 293 BCCs found the highest mutation rate in cancer (65 mutations/Mb). Eighty-five percent of the BCCs harbored mutations in Hh pathway genes (PTCH1, 73% or SMO, 20% (P = 6.6 × 10(-8)) and SUFU, 8%) and in TP53 (61%). However, 85% of the BCCs also harbored additional driver mutations in other cancer-related genes. We observed recurrent mutations in MYCN (30%), PPP6C (15%), STK19 (10%), LATS1 (8%), ERBB2 (4%), PIK3CA (2%), and NRAS, KRAS or HRAS (2%), and loss-of-function and deleterious missense mutations were present in PTPN14 (23%), RB1 (8%) and FBXW7 (5%). Consistent with the mutational profiles, N-Myc and Hippo-YAP pathway target genes were upregulated. Functional analysis of the mutations in MYCN, PTPN14 and LATS1 suggested their potential relevance in BCC tumorigenesis.
Deng J, Lei W, Xiang X, et al.Cullin 4A (CUL4A), a direct target of miR-9 and miR-137, promotes gastric cancer proliferation and invasion by regulating the Hippo signaling pathway.
Oncotarget. 2016; 7(9):10037-50 [PubMed
] Free Access to Full Article Related Publications
Although Cullin 4A (CUL4A) is mutated or amplified in several human cancer types, its role in gastric cancer (GC) and the mechanisms underlying its regulation remain largely uncharacterized. In the present study, we report that the expression of CUL4A significantly correlated with the clinical stage of the tumor and lymph node metastasis, and survival rates were lower in GC patients with higher levels of CUL4A than in patients with lower CUL4A levels. The upregulation of CUL4A promoted GC cell proliferation and epithelial-mesenchymal transition (EMT) by downregulating LATS1-Hippo-YAP signaling. Knocking down CUL4A had the opposite effect in vitro and in vivo. Interestingly, CUL4A expression was inhibited by the microRNAs (miRNAs), miR-9 and miR-137, which directly targeted the 3'-UTR of CUL4A. Overexpression of miR-9 and miR-137 downregulated the CUL4A-LATS1-Hippo signaling pathway and suppressed GC cell proliferation and invasion in vitro. Taken together, our findings demonstrate that perturbations to miR-9/137-CUL4A-Hippo signaling contribute to gastric tumorigenesis, and suggest potential therapeutic targets for the future treatment of GC.
Pancreatic cancer is one of the major malignancies and cause for mortality across the world, with recurrence and metastatic progression remaining the single largest cause of pancreatic cancer mortality. Hence it is imperative to develop novel biomarkers of pancreatic cancer prognosis. The E3 ubiquitin ligase ITCH has been previously reported to inhibit the tumor suppressive Hippo signaling by suppressing LATS1/2 in breast cancer and chronic lymphocytic leukemia. However, the role of ITCH in pancreatic cancer progression has not been described. Here we report that ITCH transcript and protein expression mimic metastatic trait in pancreatic cancer patients and cell lines. Loss-of-function studies of ITCH showed that the gene product is responsible for inducing metastasis in vivo. We furthermore show that hsa-miR-106b, which itself is down regulated in metastatic pancreatic cancer, directly interacts and inhibit ITCH expression. ITCH and hsa-miR-106b are thus potential biomarkers for pancreatic cancer prognosis.
The Hippo signaling pathway plays a crucial role in regulating tissue homeostasis, organ size, tumorigenesis and cancer chemoresistance when deregulated. Physiologically, the Hippo core kinase cassette that consists of mamma-lian STE20-like protein kinase 1/2 (MST1/2), and large tumour suppressor 1/2 (LATS1/2), together with the adaptor proteins Salvador homologue 1 (SAV1) and MOB kinase activator 1 (MOB1), tightly restricts the activities of homologous oncoproteins Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) to low levels. However, how the Hippo kinase cassette core components are simultaneously inhibited, to exhibit constitutively inactivated Hippo signaling and activated YAP/TAZ in cancer remains puzzling. Herein, we reported that miR-181c directly repressed MST1, LATS2, MOB1 and SAV1 expression in human pancreatic cancer cells. Overexpression of miR-181c induced hyperactivation of the YAP/TAZ and enhanced expression of the Hippo signaling downstream genes CTGF, BIRC5 and BLC2L1, leading to pancreatic cancer cell survival and chemoresistance in vitro and in vivo. Importantly, high miR-181c levels were significantly correlated with Hippo signaling inactivation in pancreatic cancer samples, and predicted a poor patient overall survival. These findings provide a novel mechanism for Hippo signaling inactivation in cancer, indicating not only a potentially pivotal role for miR-181c in the progression of pancreatic cancer, but also may represent a new therapeutic target and prognostic marker.
Zhang K, Qi HX, Hu ZM, et al.YAP and TAZ Take Center Stage in Cancer.
Biochemistry. 2015; 54(43):6555-66 [PubMed
] Related Publications
The Hippo pathway was originally identified and named through screening for mutations in Drosophila, and the core components of the Hippo pathway are highly conserved in mammals. In the Hippo pathway, MST1/2 and LATS1/2 regulate downstream transcription coactivators YAP and TAZ, which mainly interact with TEAD family transcription factors to promote tissue proliferation, self-renewal of normal and cancer stem cells, migration, and carcinogenesis. The Hippo pathway was initially thought to be quite straightforward; however, recent studies have revealed that YAP/TAZ is an integral part and a nexus of a network composed of multiple signaling pathways. Therefore, in this review, we will summarize the latest findings on events upstream and downstream of YAP/TAZ and the ways of regulation of YAP/TAZ. In addition, we also focus on the crosstalk between the Hippo pathway and other tumor-related pathways and discuss their potential as therapeutic targets.
Jiang L, Li W, Wu M, Cao SCiculating miRNA-21 as a Biomarker Predicts Polycystic Ovary Syndrome (PCOS) in Patients.
Clin Lab. 2015; 61(8):1009-15 [PubMed
] Related Publications
BACKGROUND: Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, hyperinsulinemia, and infertility. In PCOS, abnormal regulation of relevant genes is required for follicular development. By binding to the 3' untranslated region (3'URT), microRNAs (miRNAs) are widely involved in posttranscriptional gene regulation. However, few studies have been conducted on circulating miRNA expression in PCOS. This study aims to describe altered expression of circulating miR-21 in PCOS.
METHODS: The expression of serum miRNAs of PCOS patients were explored using the TaqMan Low Density Array followed by individual quantitative reverse transcription polymerase chain reaction assays. The protein level of LATS1 was determined using Western blot. To validate whether miR-21 targeted LATS1, the luciferase assay was applied.
RESULTS: In comparison with normal subjects, the circulating level of miRNA-21 was significantly enhanced in PCOS patients. In PCOS patients, the expression levels of MST1/2, LATS1/2, TAZ were much lower than the control subjects. Luciferase reporter assay revealed that LATS1 was a downstream target of miR-21.
CONCLUSIONS: In comparison with normal subjects, serum miR-21 is obviously increased in PCOS patients. Through targeting LATS1, miR-21 could prompt PCOS progression and could act as a novel non-invasive biomarker for diagnosis of PCOS.
The Hippo pathway regulates tissue growth and cell fate. In colon cancer, Hippo pathway deregulation promotes cellular quiescence and resistance to 5-Fluorouracil (5-Fu). In this study, 14 polymorphisms in 8 genes involved in the Hippo pathway (MST1, MST2, LATS1, LATS2, YAP, TAZ, FAT4 and RASSF1A) were evaluated as recurrence predictors in 194 patients with stages II/III colon cancer treated with 5-Fu-based adjuvant chemotherapy. Patients with a RASSF1A rs2236947 AA genotype had higher 3-year recurrence rate than patients with CA/CC genotypes (56 vs 33%, hazard ratio (HR): 1.87; P=0.017). Patients with TAZ rs3811715 CT or TT genotypes had lower 3-year recurrence rate than patients with a CC genotype (28 vs 40%; HR: 0.66; P=0.07). In left-sided tumors, this association was stronger (HR: 0.29; P=0.011) and a similar trend was found in an independent Japanese cohort. These promising results reveal polymorphisms in the Hippo pathway as biomarkers for stages II and III colon cancer.The Pharmacogenomics Journal advance online publication, 15 September 2015; doi:10.1038/tpj.2015.64.
Oh JE, Ohta T, Satomi K, et al.Alterations in the NF2/LATS1/LATS2/YAP Pathway in Schwannomas.
J Neuropathol Exp Neurol. 2015; 74(10):952-9 [PubMed
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Schwannomas are benign nerve sheath tumors composed of well-differentiated Schwann cells. Other than frequent NF2 (neurofibromatosis type 2) mutations (50%-60%), their molecular pathogenesis is not fully understood. LATS1 and LATS2 are downstream molecules of NF2 and are negative regulators of the yes-associated protein (YAP) oncogene in the Hippo signaling pathway. We assessed mutations of the NF2, LATS1, and LATS2 genes, promoter methylation of LATS1 and LATS2, and expression of YAP and phosphorylated YAP in 82 cases of sporadic schwannomas. Targeted sequencing using the Ion Torrent Proton instrument revealed NF2 mutations in 45 cases (55%), LATS1 mutations in 2 cases (2%), and LATS2 mutations in 1 case (1%) of schwannoma. Methylation-specific polymerase chain reaction showed promoter methylation of LATS1 and LATS2 in 14 cases (17%) and 25 cases (30%), respectively. Overall, 62 cases (76%) had at least 1 alteration in the NF2, LATS1, and/or LATS2 genes. Immunohistochemistry revealed nuclear YAP expression in 18 of 42 cases of schwannoma (43%) and reduced cytoplasmic phosphorylated YAP expression in 15 of 49 cases of schwannoma (31%), all of which had at least 1 alteration in the NF2, LATS1, and/or LATS2 genes. These results suggest that an abnormal Hippo signaling pathway is involved in the pathogenesis of most sporadic schwannomas.
Mutations in Adenomatous polyposis coli (APC) underlie familial adenomatous polyposis (FAP), an inherited cancer syndrome characterized by the widespread development of colorectal polyps. APC is best known as a scaffold protein in the β-catenin destruction complex, whose activity is antagonized by canonical Wnt signaling. Whether other effector pathways mediate APC's tumor suppressor function is less clear. Here we report that activation of YAP, the downstream effector of the Hippo signaling pathway, is a general hallmark of tubular adenomas from FAP patients. We show that APC functions as a scaffold protein that facilitates the Hippo kinase cascade by interacting with Sav1 and Lats1. Consistent with the molecular link between APC and the Hippo signaling pathway, genetic analysis reveals that YAP is absolutely required for the development of APC-deficient adenomas. These findings establish Hippo-YAP signaling as a critical effector pathway downstream from APC, independent from its involvement in the β-catenin destruction complex.
Mohamed AD, Tremblay AM, Murray GI, Wackerhage HThe Hippo signal transduction pathway in soft tissue sarcomas.
Biochim Biophys Acta. 2015; 1856(1):121-9 [PubMed
] Related Publications
Sarcomas are rare cancers (≈1% of all solid tumours) usually of mesenchymal origin. Here, we review evidence implicating the Hippo pathway in soft tissue sarcomas. Several transgenic mouse models of Hippo pathway members (Nf2, Mob1, LATS1 and YAP1 mutants) develop various types of sarcoma. Despite that, Hippo member genes are rarely point mutated in human sarcomas. Instead, WWTR1-CAMTA1 and YAP1-TFE3 fusion genes are found in almost all cases of epithelioid haemangioendothelioma. Also copy number gains of YAP1 and other Hippo members occur at low frequencies but the most likely cause of perturbed Hippo signalling in sarcoma is the cross-talk with commonly mutated cancer genes such as KRAS, PIK3CA, CTNNB1 or FBXW7. Current Hippo pathway-targeting drugs include compounds that target the interaction between YAP and TEAD G protein-coupled receptors (GPCR) and the mevalonate pathway (e.g. statins). Given that many Hippo pathway-modulating drugs are already used in patients, this could lead to early clinical trials testing their efficacy in different types of sarcoma.
The WWTR1 (protein is known as TAZ)-CAMTA1 (WC) fusion gene defines epithelioid hemangioendothelioma, a malignant vascular cancer. TAZ (transcriptional coactivator with PDZ binding motif) is a transcriptional coactivator and end effector of the Hippo tumor suppressor pathway. It is inhibited by phosphorylation by the Hippo kinases LATS1 and LATS2. Such phosphorylation causes cytoplasmic localization, 14-3-3 protein binding and the phorphorylation of a terminal phosphodegron promotes ubiquitin-dependent degradation (the phosphorylation of the different motifs has several effects). CAMTA1 is a putative tumor suppressive transcription factor. Here we demonstrate that TAZ-CAMTA1 (TC) fusion results in its nuclear localization and constitutive activation. Consequently, cells expressing TC display a TAZ-like transcriptional program that causes resistance to anoikis and oncogenic transformation. Our findings elucidate the mechanistic basis of TC oncogenic properties, highlight that TC is an important model to understand how the Hippo pathway can be inhibited in cancer, and provide approaches for targeting this chimeric protein.
Genomic alterations in GNAS, the gene coding for the Gαs heterotrimeric G protein, are associated with a large number of human diseases. Here, we explored the role of Gαs on stem cell fate decisions by using the mouse epidermis as a model system. Conditional epidermal deletion of Gnas or repression of PKA signalling caused a remarkable expansion of the stem cell compartment, resulting in rapid basal-cell carcinoma formation. In contrast, inducible expression of active Gαs in the epidermis caused hair follicle stem cell exhaustion and hair loss. Mechanistically, we found that Gαs-PKA disruption promotes the cell autonomous Sonic Hedgehog pathway stimulation and Hippo signalling inhibition, resulting in the non-canonical activation of GLI and YAP1. Our study highlights an important tumour suppressive function of Gαs-PKA, limiting the proliferation of epithelial stem cells and maintaining proper hair follicle homeostasis. These findings could have broad implications in multiple pathophysiological conditions, including cancer.
Miyanaga A, Masuda M, Tsuta K, et al.Hippo pathway gene mutations in malignant mesothelioma: revealed by RNA and targeted exon sequencing.
J Thorac Oncol. 2015; 10(5):844-51 [PubMed
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INTRODUCTION: Malignant mesothelioma (MM) is an aggressive neoplasm causatively associated with exposure to asbestos. MM is rarely responsive to conventional cytotoxic drugs, and the outcome remains dismal. It is, therefore, necessary to identify the signaling pathways that drive MM and to develop new therapeutics specifically targeting the molecules involved.
METHODS: We performed comprehensive RNA sequencing of 12 MM cell lines and four clinical samples using so-called next-generation sequencers.
RESULTS: We found 15 novel fusion transcripts including one derived from chromosomal translocation between the large tumor suppressor 1 (LATS1) and presenilin-1 (PSEN1) genes. LATS1 is one of the central players of the emerging Hippo signaling pathway. The LATS1-PSEN1 fusion gene product lacked the ability to phosphorylate yes-associated protein and to suppress the growth of a MM cell line. The wild-type LATS1 allele was undetectable in this cell line, indicating two-hit genetic inactivation of its tumor suppressor function. Using pathway-targeted exon sequencing, we further identified a total of 11 somatic mutations in four Hippo pathway genes (neurofibromatosis type 2 [NF2], LATS2, RASSF1, and SAV1) in 35% (8 of 23) of clinical samples. Nuclear staining of yes-associated protein was detected in 55% (24 of 44) of the clinical samples. Expression and/or phosphorylation of the Hippo signaling proteins, RASSF1, Merlin (NF2), LATS1, and LATS2, was frequently absent.
CONCLUSIONS: The frequent alterations of Hippo pathway molecules found in this study indicate the therapeutic feasibility of targeting this pathway in patients with MM.
The G protein-coupled estrogen receptor (GPER) mediates both the genomic and nongenomic effects of estrogen and has been implicated in breast cancer development. Here, we compared GPER expression in cancerous tissue and adjacent normal tissue in patients with invasive ductal carcinoma (IDC) of the breast and determined that GPER is highly upregulated in cancerous cells. Additionally, our studies revealed that GPER stimulation activates yes-associated protein 1 (YAP) and transcriptional coactivator with a PDZ-binding domain (TAZ), 2 homologous transcription coactivators and key effectors of the Hippo tumor suppressor pathway, via the Gαq-11, PLCβ/PKC, and Rho/ROCK signaling pathways. TAZ was required for GPER-induced gene transcription, breast cancer cell proliferation and migration, and tumor growth. Moreover, TAZ expression positively correlated with GPER expression in human IDC specimens. Together, our results suggest that the Hippo/YAP/TAZ pathway is a key downstream signaling branch of GPER and plays a critical role in breast tumorigenesis.
Metastasis of cancer cells involves multiple steps, including their dissociation from the primary tumor and invasion through the endothelial cell barrier to enter the circulation and finding their way to distant organ sites where they extravasate and establish metastatic lesions. Deficient contact inhibition is a hallmark of invasive cancer cells, yet surprisingly the vascular invasiveness of commonly studied cancer cell lines is regulated by the density at which cells are propagated in culture. Cells grown at high density were less effective at invading an endothelial monolayer than cells grown at low density. This phenotypic difference was also observed in a zebrafish model of vascular invasion of cancer cells after injection into the yolk sac and extravasation of cancer cells into tissues from the vasculature. The vascular invasive phenotypes were reversible. A kinome-wide RNA interference screen was used to identify drivers of vascular invasion by panning small hairpin RNA (shRNA) library-transduced noninvasive cancer cell populations on endothelial monolayers. The selection of invasive subpopulations showed enrichment of shRNAs targeting the large tumor suppressor 1 (LATS1) kinase that inhibits the activity of the transcriptional coactivator yes-associated protein (YAP) in the Hippo pathway. Depletion of LATS1 from noninvasive cancer cells restored the invasive phenotype. Complementary to this, inhibition or depletion of YAP inhibited invasion in vitro and in vivo. The vascular invasive phenotype was associated with a YAP-dependent upregulation of the cytokines IL6, IL8 and C-X-C motif ligand 1, 2 and 3. Antibody blockade of cytokine receptors inhibited invasion and confirmed that they are rate-limiting drivers that promote cancer cell vascular invasiveness and could provide therapeutic targets.
YAP (Yes-associated protein) is a transcription co-activator in the Hippo tumour suppressor pathway and controls cell growth, tissue homeostasis and organ size. YAP is inhibited by the kinase Lats, which phosphorylates YAP to induce its cytoplasmic localization and proteasomal degradation. YAP induces gene expression by binding to the TEAD family transcription factors. Dysregulation of the Hippo-YAP pathway is frequently observed in human cancers. Here we show that cellular energy stress induces YAP phosphorylation, in part due to AMPK-dependent Lats activation, thereby inhibiting YAP activity. Moreover, AMPK directly phosphorylates YAP Ser 94, a residue essential for the interaction with TEAD, thus disrupting the YAP-TEAD interaction. AMPK-induced YAP inhibition can suppress oncogenic transformation of Lats-null cells with high YAP activity. Our study establishes a molecular mechanism and functional significance of AMPK in linking cellular energy status to the Hippo-YAP pathway.
The Hippo pathway was discovered as a conserved tumour suppressor pathway restricting cell proliferation and apoptosis. However, the upstream signals that regulate the Hippo pathway in the context of organ size control and cancer prevention are largely unknown. Here, we report that glucose, the ubiquitous energy source used for ATP generation, regulates the Hippo pathway downstream effector YAP. We show that both the Hippo pathway and AMP-activated protein kinase (AMPK) were activated during glucose starvation, resulting in phosphorylation of YAP and contributing to its inactivation. We also identified glucose-transporter 3 (GLUT3) as a YAP-regulated gene involved in glucose metabolism. Together, these results demonstrate that glucose-mediated energy homeostasis is an upstream event involved in regulation of the Hippo pathway and, potentially, an oncogenic function of YAP in promoting glycolysis, thereby providing an exciting link between glucose metabolism and the Hippo pathway in tissue maintenance and cancer prevention.
Reddy VR, Annamalai T, Narayanan V, Ramanathan AHypermethylation of promoter region of LATS1--a CDK interacting protein in oral squamous cell carcinomas--a pilot study in India.
Asian Pac J Cancer Prev. 2015; 16(4):1599-603 [PubMed
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BACKGROUND: Epigenetic silencing of tumor suppressor genes due to promoter hypermethylation is one of the frequent mechanisms observed in cancers. Hypermethylation of several tumor suppressor genes involved in cell cycle regulation has been reported in many types of tumors including oral squamous cell carcinomas. LATS1 (Large Tumor Suppressor, isoform 1) is a novel tumor suppressor gene that regulates cell cycle progression by forming complexes with the cyclin dependent kinase, CDK1. Promoter hypermethylation of the LATS1 gene has been observed in several carcinomas and also has been linked with prognosis. However, the methylation status of LATS1 in oral squamous cell carcinomas is not known. As oral cancer is one of the most prevalent forms of cancer in India, the present study was designed to investigate the methylation status of LATS1 promoter and associate it with histopathological findings in order to determine any associations of the genetic status with stage of differentiation.
MATERIALS AND METHODS: Tumor chromosomal DNA isolated from biopsy tissues of thirteen oral squamous cell carcinoma biopsy tissues were subjected to digestion with methylation sensitive HpaII enzyme followed by amplification with primers flanking CCGG motifs in promoter region of LATS1 gene. The PCR amplicons were subsequently subjected to agarose gel electrophoresis along with undigested amplification control.
RESULTS: HpaII enzyme based methylation sensitive PCR identified LATS1 promoter hypermethylation in seven out of thirteen oral squamous cell carcinoma samples.
CONCLUSIONS: The identification of LATS1 promoter hypermethylation in seven oral squamous cell carcinoma samples (54%), which included one sample with epithelial dysplasia, two early invasive and one moderately differentiated lesions indicates that the hypermethylation of this gene may be one of the early event during carcinogenesis. To the best of our knowledge, this is the first study to have explored and identified positive association between LATS1 promoter hypermethylation with histopathological features in oral squamous cell carcinomas.
The large tumour suppressor 1 (LATS1) signalling network has been proved to be an essential regulator within the cell, participating in multiple cellular phenotypes. However, it is unclear concerning the clinical significance of LATS1 and the regulatory mechanisms of 17-Allylamino-17- demethoxygeldanamycin (17-AAG) in lung adenocarcinoma (LAC). The aim of the present study was to investigate the correlation of LATS1 and yes-associated protein (YAP) expression with clinicopathological characteristics in LAC patients, and the effects of 17-AAG on biological behaviours of LAC cells. Subcutaneous LAC tumour models were further established to observe the tumour growth in nude mice. The results showed that the positive expression of LATS1 was significantly lowered (26.7% versus 68.0%, P < 0.001), while that of YAP was elevated (76.0% versus 56.0%, P = 0.03) in LAC tissues compared to the adjacent non-cancerous tissues; LAST1 expression was negatively correlated with YAP expression (r = 0.432, P < 0.001) and lymphatic invasion of the tumour (P = 0.015). In addition, 17-AAG inhibited proliferation and invasion, and induced cell apoptosis and cycle arrest in LAC cells together with increased expression of E-cadherin and p-LATS1, and decreased expression of YAP and connective tissue growth factor. Tumour volumes and weight were much smaller in 17-AAG-treated groups than those in untreated group (P < 0.01). Taken together, our findings indicate that decreased expression of LATS1 is associated with lymphatic invasion of LAC, and 17-AAG suppresses growth and invasion of LAC cells via regulation of the LATS1/YAP pathway in vitro and in vivo, suggesting that we may provide a promising therapeutic strategy for the treatment of human LAC.
Lv M, Lv M, Chen L, et al.Angiomotin promotes breast cancer cell proliferation and invasion.
Oncol Rep. 2015; 33(4):1938-46 [PubMed
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Angiomotin (Amot) is a multifunctional protein involved in endothelial cell migration and tube formation and angiogenesis. However, the biological role and molecular mechanism for the abnormal expression of Amot in breast cancer is poorly understood. The aim of the present study was to examine the function of and relationship between Amot and the Hippo-Yes-associated protein (YAP) pathway. The expression and location of Amot was examined in breast cancer tissues and cell lines using immunohistochemistry, real-time polymerase chain reaction analysis (RT-PCR), western blotting and immunofluorescence. ANOVA, Student's t-test, Wilcoxon and Chi-square tests were utilized to determine the association of Amot expression with clinically relevant parameters. Stable Amot knockdown MCF-7 cells (MCF-7 Amot KD) were generated to investigate the impact of Amot downregulation on the growth and invasion of MCF-7 cells in vitro. Western blotting was applied to detect the expression of the Hippo-YAP pathway protein in the MCF-7 cells. It was observed that Amot was highly expressed in breast cancer tissues, but weakly expressed in adjacent non-cancerous tissues. Additionally, the expression level of Amot was correlated with that of Ki-67. In MCF-7 cells, Amot downregulation resulted in a significant decrease of cell proliferation and invasiveness. Following Amot knockdown in MCF-7 cells, the expression of YAP, YAP/TAZ and LATS1 was decreased. In particular, the expression of YAP was markedly reduced in the nucleoprotein. The results suggested that Amot was highly expressed in breast cancer tissues and was important in the promotion of breast cancer cell proliferation and invasion. In addition, there was a more intimate connection between Amot and Hippo-YAP pathway.
Cutaneous melanoma (CM) is the most lethal form of skin cancers. The Hippo pathway controls cell migration, development and sizes of the organs in diverse species, and deregulation of this pathway may affect CM progression and prognosis. Therefore, we hypothesized that genetic variants of Hippo pathway genes might predict survival of CM patients. We used the genotyping data of 1,115 common single nucleotide polymorphisms (SNPs) in the 12 pathway core genes (i.e., MST1, MST2, SAV1, LATS1, LATS2, MOB1A, MOB1B, YAP1, TEAD1, TEAD2, TEAD3 and TEAD4) from the dataset of our previously published CM genome-wide association study and comprehensively analyzed their associations with CM-specific survival (CSS) in 858 CM patients by using the Kaplan-Meier analyses and Cox proportional hazards regression models. We found a predictive role of YAP1 rs11225163 CC, TEAD1 rs7944031 AG+GG and TEAD4 rs1990330 CA+AA in the prognosis of CM. In addition, patients with an increasing number of unfavorable genotypes (NUG) had a markedly increased risk of death. After incorporating NUG in the model with clinical variables, the new model showed a significantly improved discriminatory ability to classify CSS (AUC increased from 82.03% to 84.56%). Our findings suggest that genetic variants of Hippo pathway genes, particularly YAP1 rs11225163, TEAD1 rs7944031 and TEAD4 rs1990330, may independently or jointly modulate survival of CM patients. Additional large, prospective studies are needed to validate these findings.
Wang C, Zhu ZM, Liu CL, et al.Knockdown of yes-associated protein inhibits proliferation and downregulates large tumor suppressor 1 expression in MHCC97H human hepatocellular carcinoma cells.
Mol Med Rep. 2015; 11(6):4101-8 [PubMed
] Free Access to Full Article Related Publications
The pathogenesis of hepatocellular carcinoma (HCC) is thought to involve the interaction of numerous genes. Identification of these genes and proteins which regulate liver carcinogenesis is critical for the exploration of novel targeted therapies. Yes‑associated protein (YAP) and large tumor suppressor 1 (LATS1) are associated with HCC cells. LATS1 is an upstream inhibitory factor of YAP in the Hippo pathway. The aim of the present study was to measure the expression of LATS1 in Yap‑downregulated cancer cells. Immunohistochemistry was used to determine YAP and LATS1 levels in HCC tissue samples. High YAP‑expressing cell lines were selected from two human hepatocellular carcinoma cells with different metastatic potential. In addition, changes in cell growth rates and LATS1 expression in human HCC 97H cells, in which YAP had been knocked down using RNA interference (RNAi). The proliferation of cells was evaluated using an MTS assay and changes in the progression of cell division were assessed through cell cycle analysis. Western blot analysis was then used to determine YAP and LATS1 expression levels in 97H cells. The results of the present study demonstrated that overexpression of YAP was negatively correlated with LATS1 expression in HCC cells (P=0.016). Knockdown of YAP using lentivirus‑small hairpin (sh)RNA significantly inhibited 97H cell growth; in addition, the downregulation of YAP protein levels (33.4%) was accompanied by downregulation of LATS1 protein levels (68.5%). In conclusion, these results demonstrated that as an inhibitor of YAP, LATS1 was decreased via downregulation of YAP using RNAi. This therefore indicated that the change in YAP levels in HCC cells may regulate LATS1 in a feedback manner.
Zhou Y, Tao F, Cheng Y, et al.Up-regulation of ITCH is associated with down-regulation of LATS1 during tumorigenesis and progression of cervical squamous cell carcinoma.
Clin Invest Med. 2014; 37(6):E384-94 [PubMed
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PURPOSE: The molecular basis for the normal cervical squamous epithelium advance to cervical intraepithelial neoplasia (CIN I, CIN II, CIN III) and ultimately to invasive carcinoma has not yet been defined. We explored the abnormal expression of ITCH (AIP4) and its degrading substrate Large Tumor Suppressor 1 (LATS1) in CINs and cervical cancers, which might disrupt the normal differentiation of the cervical epithelia and contribute to the tumorigenesis of the cervix.
METHODS: A series of 110 samples, comprising 24 cases of normal cervical tissues, 20 cases of CIN I, 26 cases of CIN II/ III and 40 cases of squamous cancer of the cervix (SCC) were used for analysis. The expression of ITCH and LATS1 was assessed in the tissues by immunohistochemistry, and statistically analyzed by SPSS13.0.
RESULTS: The increased nuclear and cytoplasmic expression levels of ITCH and the low membrane expression of LATS1 were strongly associated with the malignant transformation of the cervical epithelium and the histological progression of SCC. Moreover, the high nuclear and cytoplasmic expression levels of ITCH were significantly correlated with clinical stage (P=0.036, P=0.003, respectively) and tumor size (P=0.046,P=0.039, respectively); the low membrane expression of LATS1 was significantly correlated with clinical stage (P=0.036)and tumor size (P=0.023). Both the nuclear and cytoplasmic expression levels of ITCH were inversely associated with the membrane expression of LATS1 in cervical tissues (P<0.001, P<0.001, respectively).
CONCLUSIONS: ITCH up-regulation and LATS1 down-regulation were closely associated with tumorigenesis and progression of SCC; therefore, inhibiting the expression of ITCH may serve as a novel therapeutic strategy for impeding the progression of precancerous neoplasm to SCC.
Yuan Y, Zhong W, Ma G, et al.Yes-associated protein regulates the growth of human non-small cell lung cancer in response to matrix stiffness.
Mol Med Rep. 2015; 11(6):4267-72 [PubMed
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The Yes‑associated protein (YAP) transcriptional coactivator is recognized as a crucial regulator of human cancer. However, its involvement in human non‑small cell lung cancer (NSCLC) in response to physical cues remains unclear. In this study, substrates with different rigidity were generated in order to evaluate the role of YAP, and its upstream regulators in the Hippo pathway, in the regulation of growth of an NSCLC cell line within particular environments. It was shown that the expression of the YAP protein in SPCA-1 NSCLC cells was significantly increased when cultured on a stiff substrate compared to a soft substrate. However, the expression of phospho‑YAP protein and large tumor suppressor kinase 1 (LATS1) were markedly decreased after culturing on the stiff substrate. Phosphorylation of YAP by LATS1 leads to cytoplasmic retention of YAP, which inhibits its function as a nuclear transcription coactivator. The study also found that the stiff substrate promoted the growth of NSCLC cells in vitro, and an increase in the transcription levels of Survivin, connective tissue growth factor, amphiregulin and Ki67, as well as a decrease in the expression level of YAP in the cytoplasm, and adecrease in p-YAP. In conclusion, the findings showed that the stiffness of the subcellular matrix altered the behavior of NSCLC cells, and that YAP regulated the growth of NSCLC cells in response to matrix stiffness, thereby suggesting a role for the Hippo‑YAP pathway in the response of NSCLC cell growth to specific microenvironments.
The core components of the Hippo pathway are conserved from flies to mammals. In humans, these include a kinase cascade initiated by the Hippo kinase MST1/2 associated with the adaptor protein WW45/SAV1, and LATS1/2 in complex with MOB1, which in turn, phosphorylates and inhibits the mammalian transcription co-activator YAP and its related protein TAZ. YAP plays a critical role in organ size control during development, and its persistent nuclear localization and activation contributes to multiple human malignancies. The mechanisms driving YAP activation in most cancers, however, are often not clearly understood. In recent studies, we and Guan's team found that YAP activation represents a key molecular event contributing to uveal melanoma, the most frequent ocular malignancy in adults. Uveal melanoma growth is driven by gain-of-function mutations in GNAQ or GNA11 oncogenes, encoding persistently active G protein α subunits of the Gq family. As the signaling capacity of G proteins and their coupled receptors (GPCRs) has been extensively investigated, these findings provided an opportunity to identify cancer-associated mechanisms resulting in YAP activation, and to explore whether YAP represents a suitable oncotarget for cancer treatment.
Zhu C, Li L, Zhao BThe regulation and function of YAP transcription co-activator.
Acta Biochim Biophys Sin (Shanghai). 2015; 47(1):16-28 [PubMed
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The Hippo pathway was initially identified in Drosophila by genetic mosaic screens for tumor suppressor genes. Researches indicated that the Hippo pathway is a key regulator of organ size and is conserved during evolution. Furthermore, studies of mouse models and clinical samples demonstrated the importance of Hippo pathway dysregulation in human cancer development. In addition, the Hippo pathway contributes to progenitor cell and stem cell self-renewal and is thus involved in tissue regeneration. In the Hippo pathway, MST1/2 kinases together with the adaptor protein SAV phosphorylate LATS1/2 kinases. Interaction with an adaptor protein MOB is also important for LATS1/2 activation. Activated LATS1/2 in turn phosphorylate and inhibit Yes-associated protein (YAP). YAP is a key downstream effector of the Hippo pathway, and is a transcriptional co-activator that mainly interacts with TEAD family transcription factors to promote gene expression. Alteration of gene expression by YAP leads to cell proliferation, apoptosis evasion, and also stem cell amplification. In this review, we mainly focus on YAP, discussing its regulation and mechanisms of action in the context of organ size control, tissue regeneration and tumorigenesis.
In recent years, human cancer genome projects provide unprecedented opportunities for the discovery of cancer genes and signaling pathways that contribute to tumor development. While numerous gene mutations can be identified from each cancer genome, what these mutations mean for cancer is a challenging question to address, especially for those from less understood putative new cancer genes. As a powerful approach, in silico bioinformatics analysis could efficiently sort out mutations that are predicted to damage gene function. Such an analysis of human large tumor suppressor genes, LATS1 and LATS2, has been carried out and the results support a role of hLATS1//2 as negative growth regulators and tumor suppressors.
Hong L, Cai Y, Jiang M, et al.The Hippo signaling pathway in liver regeneration and tumorigenesis.
Acta Biochim Biophys Sin (Shanghai). 2015; 47(1):46-52 [PubMed
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The Hippo signaling pathway is an evolutionarily conserved signaling module that plays critical roles in liver size control and tumorigenesis. The Hippo pathway consists of a core kinase cascade in which the mammalian Ste20-like kinases (Mst1/2, orthologs of Drosophila Hippo) and their cofactor Salvador (Sav1) form a complex to phosphorylate and activate the large tumor suppressor (Lats1/2). Lats1/2 kinases in turn phosphorylate and inhibit the transcription co-activators, the Yes-associated protein (YAP) and the transcriptional co-activator with PDZ-binding motif (TAZ), two major downstream effectors of the Hippo pathway. Losses of the Hippo pathway components induce aberrant hepatomegaly and tumorigenesis, in which YAP coordinates regulation of cell proliferation and apoptosis and plays an essential role. This review summarizes the current findings of the regulation of Hippo signaling in liver regeneration and tumorigenesis, focusing on how the loss of tumor suppressor components of the Hippo pathway results in liver cancers and discussing the molecular mechanisms that regulate the expression and activation of its downstream effector YAP in liver tumorigenesis.
Kong D, Zhao Y, Men T, Teng CBHippo signaling pathway in liver and pancreas: the potential drug target for tumor therapy.
J Drug Target. 2015; 23(2):125-33 [PubMed
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Cell behaviors, including proliferation, differentiation and apoptosis, are intricately controlled during organ development and tissue regeneration. In the past 9 years, the Hippo signaling pathway has been delineated to play critical roles in organ size control, tissue regeneration and tumorigenesis through regulating cell behaviors. In mammals, the core modules of the Hippo signaling pathway include the MST1/2-LATS1/2 kinase cascade and the transcriptional co-activators YAP/TAZ. The activity of YAP/TAZ is suppressed by cytoplasmic retention due to phosphorylation in the canonical MST1/2-LATS1/2 kinase cascade-dependent manner or the non-canonical MST1/2- and/or LATS1/2-independent manner. Hippo signaling pathway, which can be activated or inactivated by cell polarity, contact inhibition, mechanical stretch and extracellular factors, has been demonstrated to be involved in development and tumorigenesis of liver and pancreas. In addition, we have summarized several small molecules currently available that can target Hippo-YAP pathway for potential treatment of hepatic and pancreatic cancers, providing clues for other YAP initiated cancers therapy as well.