Aberrant Hepatocyte Growth Factor Research Articles

Lidocaine attenuates TMZ resistance and inhibits cell migration by modulating the MET pathway in glioblastoma cells.

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumor. Currently, the predominant clinical treatment is the combination of surgical resection with concurrent radiotherapy and chemotherapy, using temozolomide (TMZ) as the primary chemotherapy drug. Lidocaine, a widely used amide‑based local anesthetic, has been found to have a significant anticancer effect. It has been reported that aberrant hepatocyte growth factor (HGF)/mesenchymal‑epithelial transition factor (MET) signaling plays a role in the progression of brain tumors. However, it remains unclear whether lidocaine can regulate the MET pathway in GBM. In the present study, the clinical importance of the HGF/MET pathway was analyzed using bioinformatics. By establishing TMZ‑resistant cell lines, the impact of combined treatment with lidocaine and TMZ was investigated. Additionally, the effects of lidocaine on cellular function were also examined and confirmed using knockdown techniques. The current findings revealed that the HGF/MET pathway played a key role in brain cancer, and its activation in GBM was associated with increased malignancy and poorer patient outcomes. Elevated HGF levels and activation of its receptor were found to be associated with TMZ resistance in GBM cells. Lidocaine effectively suppressed the HGF/MET pathway, thereby restoring TMZ sensitivity in TMZ‑resistant cells. Furthermore, lidocaine also inhibited cell migration. Overall, these results indicated that inhibiting the HGF/MET pathway using lidocaine can enhance the sensitivity of GBM cells to TMZ and reduce cell migration, providing a potential basis for developing novel therapeutic strategies for GBM.

Targeting c-Met on gastric cancer cells through a fully human fab antibody isolated from a large naive phage antibody library.

The aberrant Hepatocyte growth factor (HGF)/ mesenchymal-epithelial transition factor (c-Met) signaling pathway in various malignancies and its correlation with tumor invasion and poor prognosis has validated c-Met as a compelling therapeutic target. Up to now, several monoclonal antibodies and small molecule inhibitors targeting c-Met have been introduced with different outcomes, none are yet clinically approved. Toward the generation of novel fully human anti-c-Met molecules, we generated a large naïve Fab antibody library using phage display technology, which subsequently screened for novel Fabs against c-Met. A phage library, with a functional size of 5.5 × 1010 individual antibody clones, was prepared using standard protocols and screened for c-Met-specific Fabs by successive rounds of panning. A panel of Fabs targeting c-Met were isolated, from which four clones were selected and further characterized by DNA sequencing. The c-Met binding ability of our selected Fabs was evaluated by c-Met ELISA assay and flow cytometry techniques. Among the confirmed anti-c-Met Fabs, clone C16, showed the highest affinity (Kaff: 0.3 × 109M-1), and 63% binding to MKN45 cells (a human gastric adenocarcinoma cell-line) as compared to c-Met negative T47D cell-line (9.03%). Together, our study presents a single-pot antibody library, as a valuable source for finding a range of antigen-specific Fab antibodies, and also, a fully human, high affinity and specific anti c-Met Fab antibody, C16, which has the potential of developing as a therapeutic or chemotherapeutic delivery agent for killing c-Met-positive tumor cells.

Aberrant activation of hepatocyte growth factor/MET signaling promotes β-catenin–mediated prostatic tumorigenesis

Co-occurrence of aberrant hepatocyte growth factor (HGF)/MET proto-oncogene receptor tyrosine kinase (MET) and Wnt/β-catenin signaling pathways has been observed in advanced and metastatic prostate cancers. This co-occurrence positively correlates with prostate cancer progression and castration-resistant prostate cancer development. However, the biological consequences of these abnormalities in these disease processes remain largely unknown. Here, we investigated the aberrant activation of HGF/MET and Wnt/β-catenin cascades in prostate tumorigenesis by using a newly generated mouse model in which both murine Met transgene and stabilized β-catenin are conditionally co-expressed in prostatic epithelial cells. These compound mice displayed accelerated prostate tumor formation and invasion compared with their littermates that expressed only stabilized β-catenin. RNA-Seq and quantitative RT-PCR analyses revealed increased expression of genes associated with tumor cell proliferation, progression, and metastasis. Moreover, Wnt signaling pathways were robustly enriched in prostate tumor samples from the compound mice. ChIP-qPCR experiments revealed increased β-catenin recruitment within the regulatory regions of the Myc gene in tumor cells of the compound mice. Interestingly, the occupancy of MET on the Myc promoter also appeared in the compound mouse tumor samples, implicating a novel role of MET in β-catenin-mediated transcription. Results from implanting prostate graft tissues derived from the compound mice and controls into HGF-transgenic mice further uncovered that HGF induces prostatic oncogenic transformation and cell growth. These results indicate a role of HGF/MET in β-catenin-mediated prostate cancer cell growth and progression and implicate a molecular mechanism whereby nuclear MET promotes aberrant Wnt/β-catenin signaling-mediated prostate tumorigenesis.

Safety and Tolerability of c-MET Inhibitors in Cancer.

The role of aberrant hepatocyte growth factor receptor (c-MET, also known as tyrosine-protein kinase MET)/hepatocyte growth factor (HGF) signaling in cancer progression and invasion has been extensively studied. c-MET inhibitors have shown promising pre-clinical and early phase clinical trial anti-tumor activity in several tumor types, although results of most phase III trials with these agents have been negative. To date, two small molecule c-MET inhibitors, cabozantinib and crizotinib, have been approved by regulatory authorities for the treatment of selected cancer types, but several novel c-MET inhibitors (either monoclonal antibodies or small molecule c-MET tyrosine kinase inhibitors) and treatment combinations are currently under study in different settings. Here we provide an overview of the mechanism of action and rationale of c-MET inhibition in cancer, the efficacy of approved agents, and novel promising c-MET-inhibitors and novel targeted combination strategies under development in different cancer types, with a focus on the safety profile and tolerability of these compounds.

Epigenetic activation of hepatocyte growth factor is associated with epithelial-mesenchymal transition and clinical outcome in non-small cell lung cancer.

Hepatocyte growth factor (HGF) expression is repressed in normal differentiated lung epithelial cells, but its expression is aberrantly upregulated in non-small cell lung cancer (NSCLC) and acts as a poor prognostic factor. The underlying molecular mechanisms of aberrant HGF expression are unclear. In this study, a novel differential methylation region located in the HGF promoter was identified, which was associated with aberrant HGF expression in NSCLC. The correlations of HGF promoter methylation detected by methylation specific PCR and HGF expression detected by immunohistochemistry with clinical outcomes were assessed in NSCLC patients. DNA methylation of the HGF promoter was correlated with the activation of HGF expression, which induced epithelial-mesenchymal transition, cell migration and invasion. According to the clinical correlation analysis in 63 NSCLC patients, those with high methylation were more likely to have stages III and IV (51.6% vs. 25.0%, P<0.05) and metastasis (57.5% vs. 16.7%, P<0.05) than patients with low methylation. In addition, compared with the protein marker of HGF expression, the DNA methylation marker of the HGF promoter had higher specificity for prognostic analysis of metastases in NSCLC. Our study indicated the regulatory mechanisms related to DNA methylation of the HGF promoter for HGF expression in NSCLC epithelial cells, and suggested that the DNA methylation signature of the HGF promoter could potentially be employed as a biomarker to improve the prognostic accuracy of NSCLC.

Preclinical Evaluation of AMG 337, a Highly Selective Small Molecule MET Inhibitor, in Hepatocellular Carcinoma.

Aberrant hepatocyte growth factor (HGF)/MET signaling has been implicated in hepatocarcinogenesis, suggesting that MET may serve as an attractive therapeutic target in hepatocellular carcinoma. We sought to investigate the in vitro and in vivo antitumor activity of AMG 337, a potent and highly selective small molecule MET kinase inhibitor, in preclinical models of hepatocellular carcinoma. The antiproliferative activity of AMG 337 was evaluated across a panel of hepatocellular carcinoma cell lines in a viability assay. Daily oral administration was used to evaluate the in vivo antitumor activity of AMG 337 in two patient-derived xenograft (PDX) models of hepatocellular carcinoma (LI0612 and LI1078). AMG 337 exerted potent antiproliferative activity against 2 of 40 hepatocellular carcinoma cell lines, namely, MHCC97H (IC50, 0.015 μmol/L) and HCCLM3 (IC50, 0.025 μmol/L). Both sensitive cell lines showed MET amplification (MET/CEN-7 >2.0) assessed by FISH, and high MET expression (3+ IHC) assessed by IHC. AMG 337 potently inhibited p-MET in all cell lines with detectable levels of total MET. However, the dose-dependent inhibition of downstream effectors of HGF/MET signaling, including p-GAB1, p-AKT, and p-ERK, was limited to those cell lines sensitive to AMG 337 in a viability assay (MHCC97H and HCCLM3). AMG 337 significantly inhibited tumor growth at all doses tested in the MET-amplified and MET-high-expressing hepatocellular carcinoma PDX model LI0612 and had no effect on tumor growth in the non-MET-amplified and MET-low-expressing hepatocellular carcinoma PDX model LI1078. AMG 337 represents a promising and novel therapeutic strategy for targeting hepatocellular carcinomas with a dependence on HGF/MET signaling. Mol Cancer Ther; 15(6); 1227-37. ©2016 AACR.

Abstract 5391: Preclinical evaluation of AMG 337, a highly selective small molecule MET inhibitor, in hepatocellular carcinoma

Abstract Purpose: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Aberrant hepatocyte growth factor / MET signaling has been implicated in hepatocarcinogenesis, suggesting that MET may serve as an attractive therapeutic target in HCC. The purpose of this study was to investigate the anti-tumor activity in vitro and in vivo of AMG 337, a potent and highly selective small molecule MET kinase inhibitor, in preclinical models of HCC. Experimental Design: The anti-proliferative activity of AMG 337 was evaluated across a panel of 40 HCC cell lines in a 72-hour viability assay. Daily oral administration of AMG 337 at doses of 3, 10 and 30 mg/kg was used to evaluate the in vivo anti-tumor activity of AMG 337 in two patient-derived mouse xenograft (PDX) models of HCC, LI0612 and LI1078. Effects on MET signaling were assessed by western blot analysis of downstream effector proteins including p-GAB1, p-AKT and p-ERK. MET protein levels and gene copy number for both PDX models and a subset of HCC cell lines were assessed by immunohistochemistry (IHC; Dako) and fluorescence in situ hybridization (FISH; Dako), respectively. High MET expression was defined as the presence of any tumor cells with membrane staining at 3+ intensity. MET amplification was defined as MET:CEN-7 ratio &amp;gt;2.0 or MET SNP array log2 copy number &amp;gt;2.5. Results: AMG 337 displayed potent anti-proliferative activity in two of 40 HCC cell lines (MHCC97H and HCCLM3) (IC50 0.015 μM and 0.025 μM, respectively); both cell lines were amplified for MET (MET/CEN-7 &amp;gt;2.0) and showed high MET expression (3+ IHC). AMG 337 potently inhibited p-MET in all cell lines with detectable levels of total MET. However, dose-dependent inhibition of p-GAB1, p-AKT and p-ERK was limited to those cell lines that were sensitive to AMG 337 in viability assays. AMG 337 significantly inhibited tumor growth at all doses tested (p &amp;lt; 0.001) in the MET-amplified and MET-high expressing HCC PDX model LI0612. However, AMG 337 had no effect on tumor growth in the non-MET-amplified and MET-low expressing HCC PDX model LI1078. Analysis of The Cancer Genome Atlas (TCGA) data identified four of 164 (2.4%) HCC tumor samples with MET amplification (https://tcga-data.nci.nih.gov/tcga), representing a patient population with potential to derive clinical benefit from AMG 337. Conclusions: These preclinical studies show that the efficacy of AMG 337 in HCC was highly associated with MET amplification. AMG 337 represents a promising, novel clinical therapeutic strategy for targeting HCC with a dependence on the MET pathway. Citation Format: Zhiqiang Du, Sean Caenepeel, Yuqing Shen, Karen Rex, Yanni Zhang, En-Tzu Tang, Ouhong Wang, Wenge Zhong, Hui Zhou, Jacqueline Huang, Eric Huang, Liaoyuan Hu, Angela Coxon, Mingqiang Zhang. Preclinical evaluation of AMG 337, a highly selective small molecule MET inhibitor, in hepatocellular carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5391. doi:10.1158/1538-7445.AM2015-5391

Abstract P6-01-20: A role of MACC1 expression and its regulation of the HGF/c-Met pathway in breast cancer

Abstract Background The newly identified gene, metastasis-associated in colon cancer 1 (MACC1), is suggested to be a transcriptional regulator of the receptor tyrosine kinase gene c-Met, leading to cancer progression and metastasis in colorectal cancer. Also in breast cancer, aberrant hepatocyte growth factor (HGF) / c-Met signaling has been shown to contribute to worse prognosis and confer resistance to endocrine therapy or trastuzumab treatment, however, little is known of the role of MACC1. Here, we report its impact on the survival for breast cancer patients and the biological function in the cell lines. Methods A total of 300 breast cancer patients who received both surgery and adjuvant treatment at Kumamoto University Hospital between 2001 and 2009 were selected. We analyzed expressions of MACC1 by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) to evaluate the associations of its expression with breast cancer survival. In an in vitro study, the expressions of MACC1 were examined by Western blotting in breast and colorectal cancer cell lines. After transfection with a MACC1-harboing plasmid, we evaluated the activities of cMet protein and cell motility and proliferation. Further, the binding ability of MACC1 to the cMet promoter was evaluated using chromatin immunoprecipitation (ChIP) assay. Results In survival analyses, reduced MACC1 expressions were associated with patient mortality. Cox proportional hazards model showed that MACC1 mRNA (HR = 0.25, P = 0.001), MACC1 protein (HR = 0.37, P = 0.016), as well as axillary nodal status and estrogen receptor status, were independent predictors of mortality. No significant correlations between MACC1 expression and other clinicopathological factors were found. We found no strong positive correlation between MACC1 protein and c-Met mRNA expression with a Spearman’s coefficient of 0.16 (P = 0.0067). In the cell lines tested, MACC1 expression was much higher in colorectal cancer cells (DLD-1) than breast cancer cells (MCF7 and MDA-MB-231). To investigate the impact of MACC1 on the biological function of the cells, we transfected with MACC1 in breast cancer and colorectal cancer cells (SW480). MACC1 overexpression did not induce cMet expression in MCF7, whereas the corresponding cMet expression was upregulated in SW480 cells. Further, SW480 cells transfected with MACC1 showed enhanced migratory ability, whereas in MDA-MB-231 cells, transfection of MACC1 had no impact on this ability. In ChIP assay, the binding of MACC1 to the cMet promoter region was suggested in SW480 cells, but not in MCF7 cells. Conclusions Our findings provide some novel insights into the role of MACC1 for breast cancer, indicating that it plays different roles in breast cancer and in several other cancers. The biological mechanism of MACC1 which underlies improvement of breast cancer prognosis remains unelucidated. There is possibility that MACC1 does not act as the exclusive master regulator of the HGF/c-Met signaling involved in disease progression in breast cancer. Further studies to validate our results are needed. Citation Format: Aiko Sueta, Yutaka Yamamoto, Mitsuhiro Hayashi, Takashi Takeshita, Mutsuko Ibusuki, Hirotaka Iwase. A role of MACC1 expression and its regulation of the HGF/c-Met pathway in breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P6-01-20.

Future directions in the evaluation of c-MET-driven malignancies.

The c-MET (mesenchymal-epithelial transition factor) receptor tyrosine kinase is an exciting novel drug target in view of its key role in oncogenesis, as well as its association with disease prognosis in a number of malignancies. Several drugs targeting c-MET are currently showing promise in clinical trials and will hopefully validate positive observations from preclinical studies. The potential efficacy of these different therapeutic agents is expected to be influenced by the mechanism of aberrant hepatocyte growth factor (HGF)/c-MET signaling pathway activation in a particular cancer, but presents a promising strategy for cancer treatment either as a single agent or as part of a combination therapeutic approach. However, there is an ongoing need to improve and accelerate the transition of preclinical research into improved therapeutic strategies for patients with cancer. The main challenges facing the development of HGF/c-MET-targeted agents for cancer treatment include the discovery of rationally designed anticancer drugs and combination strategies, as well as the validation of predictive biomarkers. This paper discusses these issues, with a particular focus on future directions in the evaluation of c-MET-driven malignancies.

Aberrant Expression of Hepatocyte Growth Factor Induces Autocrine MET Activation Providing a Novel Therapeutic Target In Acute Myeloid Leukemia.

AbstractAbstract 1042Despite improvements in the treatment of acute myeloid leukemia (AML), high risk disease such as complex aberrant karyotype AML remains largely refractory to current therapy, and is mostly fatal. Identification of effective therapeutic targets by using candidate gene approaches has been limited by the number and variety of genetic defects associated with AML. Thus, we carried out a genome-wide functional screen in complex karyotype AML using a retroviral library of short hairpin RNAs (shRNAs), and discovered that shRNA-mediated depletion of hepatocyte growth factor (HGF) specifically inhibits growth of AML cells but not a panel of lymphoid cancer cells. HGF was to found to be aberrantly expressed in about 15% of patients with AML, including most patients with complex karyotype disease. In contrast to normal CD34+ cells that express MET (but not HGF), 5 of 7 cell lines derived from patients with complex karyotype AML exhibited aberrant expression of HGF that was associated with autocrine activation of its receptor MET. Depletion of HGF or MET using multiple independent shRNAs profoundly reduced proliferation and induced cell death in AML cells lines that express HGF but not those that lack HGF expression. Inhibition of MET using the tyrosine kinase inhibitor (SU11274) or HGF using neutralizing anti-HGF antibody (R&D Systems) also inhibited growth and induced apoptosis in AML cell lines dependent on HGF/MET activation but not those that lack HGF expression. Thus, aberrant HGF expression causes autocrine MET activation and oncogene dependence in a subset of patients with AML, confers sensitivity to HGF/MET inhibition, and provides a novel therapeutic target for this otherwise lethal disease. Disclosures:No relevant conflicts of interest to declare.

The PI3K–Akt mediates oncogenic Met-induced centrosome amplification and chromosome instability

The oncogenic ability of aberrant hepatocyte growth factor receptor (Met) signaling is thought to mainly rely on its mitogenic and anti-apoptotic effects. Recently, however, cumulating evidences suggest that genomic instability may be a crucial factor in tumorigenesis. Here, we address whether oncogenic Met receptor is linked to the centrosome abnormality and genomic instability. We showed that expression of the constitutive active Met (CA-Met) induced supernumerary centrosomes probably due to deregulated centrosome duplication, which was accompanied with multipolar spindle formation and aneuploidy. Interestingly, LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, significantly suppressed the appearance of supernumerary centrosomes. Moreover, knockdown of Akt with small interfering RNAs and overexpression of phosphatase and tensin homolog or dominant-negative Akt abrogated supernumerary centrosome formation, evidencing the involvement of PI3K signaling. We further showed that expression of CA-Met significantly increased aneuploidy in p53(-/-) HCT116 cells, but not in p53(+/+) HCT116 cells, indicating that the ability of CA-Met to induce chromosomal instability (CIN) phenotype is related with p53 status. Together, our data demonstrate that aberrant hepatocyte growth factor/Met signaling induces centrosome amplification and CIN via the PI3K-Akt pathway, providing an example that oncogenic growth factor signals prevalent in a wide variety of cancers have cross talks to centrosome abnormality and CIN.

SU5416 is a potent inhibitor of hepatocyte growth factor receptor (c-Met) and blocks HGF-induced invasiveness of human HepG2 hepatoma cells

Background/Aims SU5416 is a potent inhibitor of receptor tyrosine kinases, including those of the vascular endothelial growth factor receptor, stem cell factor receptor, and platelet-derived growth factor receptor. Because of the overwhelming evidence favoring the role of aberrant hepatocyte growth factor (HGF)/Met signaling in the pathogenesis of various human cancers, various inhibitor strategies have been employed to therapeutically target this receptor. Methods Cell proliferation was determined by incorporation of [ 3H] thymidine. Invasiveness was assayed in Boyden Chambers with 8 μm Matrigel coated filters. Phosphorylation of ERK1/2, Akt by HGF stimulation was detected by Western blotting. Results We found that SU5416 inhibited motility scattering and the invasive activity of a hepatocellular carcinoma cell line HepG2 in vitro and growth in primary cultured hepatocytes induced by HGF. Consequently, tyrosine autophosphorylation of the c-met induced by HGF was inhibited in these cells by SU5416 in a dose-dependent manner. Furthermore, ERK1/2 and Akt phosphorylation, the signaling events down-stream of c-met activation were reduced. Moreover, SU5416 caused reversion in NIH3T3 fibroblasts transformed by the oncogenic form of the receptor, Tpr-Met. Conclusions Inhibition of various solid tumors growth and metastasis by SU5416 may be partially attributed to blocking activation of the hepatocyte growth factor receptor.

SU5416 is a potent inhibitor of hepatocyte growth factor receptor (c-Met) and blocks HGF-induced invasiveness of human HepG2 hepatoma cells

Background/Aims SU5416 is a potent inhibitor of receptor tyrosine kinases, including those of the vascular endothelial growth factor receptor, stem cell factor receptor, and platelet-derived growth factor receptor. Because of the overwhelming evidence favoring the role of aberrant hepatocyte growth factor (HGF)/Met signaling in the pathogenesis of various human cancers, various inhibitor strategies have been employed to therapeutically target this receptor. Methods Cell proliferation was determined by incorporation of [3H] thymidine. Invasiveness was assayed in Boyden Chambers with 8 μm Matrigel coated filters. Phosphorylation of ERK1/2, Akt by HGF stimulation was detected by Western blotting. Results We found that SU5416 inhibited motility scattering and the invasive activity of a hepatocellular carcinoma cell line HepG2 in vitro and growth in primary cultured hepatocytes induced by HGF. Consequently, tyrosine autophosphorylation of the c-met induced by HGF was inhibited in these cells by SU5416 in a dose-dependent manner. Furthermore, ERK1/2 and Akt phosphorylation, the signaling events down-stream of c-met activation were reduced. Moreover, SU5416 caused reversion in NIH3T3 fibroblasts transformed by the oncogenic form of the receptor, Tpr-Met. Conclusions Inhibition of various solid tumors growth and metastasis by SU5416 may be partially attributed to blocking activation of the hepatocyte growth factor receptor.

Stanniocalcin 1 Is an Autocrine Modulator of Endothelial Angiogenic Responses to Hepatocyte Growth Factor

Stanniocalcin 1 (STC1) is a secreted glycoprotein originally described as a hormone involved in calcium and phosphate homeostasis in bony fishes. We recently identified the mammalian homolog of this molecule to be highly up-regulated in an in vitro model of angiogenesis, as well as focally and intensely expressed at sites of pathological angiogenesis (e.g. tumor vasculature). In the present study, we report that STC1 is a selective modulator of hepatocyte growth factor (HGF)-induced endothelial migration and morphogenesis, but not proliferation. STC1 did not inhibit proliferative or migratory responses to vascular endothelial growth factor or basic fibroblast growth factor. The mechanism of STC1 inhibitory effects on HGF-induced endothelial migration seem to occur secondary to receptor activation because STC1 did not inhibit HGF-induced c-met receptor phosphorylation, but did block HGF-induced focal adhesion kinase activation. In the mouse femoral artery ligation model of angiogenesis, STC1 expression closely paralleled that of the endothelial marker CD31, and the peak level of STC1 expression occurred after an increase in HGF expression. We propose that STC1 may play a selective modulatory role in angiogenesis, possibly serving as a "stop signal" or stabilizing factor contributing to the maturation of newly formed blood vessels. HGF is a mesenchyme-derived pleiotropic factor with mitogenic, motogenic, and morphogenic activities on a number of different cell types. HGF effects are mediated through a specific tyrosine kinase, c-met, and aberrant HGF and c-met expression are frequently observed in a variety of tumors. Recent studies have shown HGF to be a potent growth factor implicated in wound healing, tissue regeneration, and angiogenesis.