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Project Details
Funding Scheme : General Research Fund
Project Number : 783613
Project Title(English) : Clinical relevance and functions of nuclear Met in hepatocellular carcinoma metastasis 
Project Title(Chinese) : 核Met在肝细胞癌转移中的临床相关性和功能角色研究 
Principal Investigator(English) : Prof YAM, Judy Wai Ping  
Principal Investigator(Chinese) :  
Department : Department of Pathology
Institution : The University of Hong Kong
E-mail Address : judyyam@pathology.hku.hk 
Tel : 22552681 
Co - Investigator(s) :
Prof Wong, Alice Sze-Tsai
Panel : Biology & Medicine
Subject Area : Medicine, Dentistry & Health
Exercise Year : 2013 / 14
Fund Approved : 1,108,944
Project Status : Completed
Completion Date : 31-10-2016
Project Objectives :
To evaluate the clinicopathological relevance and prognostic significance of nMet in HCC.
To characterize the functional role of nMet in HCC invasiveness and metastasis.
To delineate the molecular pathways of nMet in HCC.
Abstract as per original application
(English/Chinese):
肝细胞癌（HCC）在东南亚地区发病率非常高，成为香港因病死亡的第二杀手。高复发率和转移率导致HCC患者的总体预后很差。Met是肝细胞生长因子（HGF）的受体酪氨酸激酶，HGF可以激活Met，从而继发大范围的生理信号级联反应。人类肿瘤通常伴有HGF-Met信号通路紊乱，因而，Met成为一个潜在的肿瘤治疗靶点，并且正在开展应用Met拮抗剂治疗肿瘤的临床试验。然而，越来越多的研究表明核Met在某些肿瘤组织和细胞系中存在表达，这说明在细胞核内，核Met还有些未知功能。这一发现无疑对当前针对于细胞表面Met受体的治疗方法提出了质疑和挑战。研究发现，细胞核Met来源于Met受体的蛋白裂解，但Met的加工过程及其从细胞表面转移至核内的机制尚不清楚，且核Met的绝大部分功能也是未知的。仅有零星研究发现，核Met具有生物活性。 Met已经被证实在HCC中呈过表达状态，但核Met表达情况未见报道。我们研究发现，在HCC中确实存在核Met过表达，而且与HCC进展和静脉侵袭有关。只有在使用针对Met羧基末端的抗体时，才能检测到核Met，表明核Met仅仅参与构成Met蛋白胞浆部分的羧基端。不论HGF存在与否，均可以在细胞核裂解物或胞核显像中检测到较Met具有更低分子量的核Met。在功能方面，核Met的表达能够促进HCC细胞侵袭，因此，我们推测，核Met通过在细胞核中发挥作用而促进了HCC的发生和转移。本项目旨在阐明核Met在HCC中的功能角色和分子途径。为此，我们将（1）评估核Met与HCC的临床相关性；（2）明确核Met在HCC转移中的作用；（3）描绘核Met参与HCC发生发展的分子途径。据我们所知，这是首次报道核Met在HCC中的功能研究，本研究将揭示肝癌崭新的发生发展机制，为HCC的治疗干预措施提供新的视角。
Realisation of objectives: 1. To evaluate the clinicopathological relevance and prognostic significance of nMet in HCC To evaluate the clinicopathological relevance and prognostic significance of nMet in HCC Immunohistochemistry of nMet was performed using tissue microarray comprising 103 cases of paired HCC tissues and corresponding non-tumorous liver tisses. Statistical analysis of nMet overexpression with clinicopathological parameters was performed. The study on this objective was successfully accomplished. 2. To characterize the functional role of nMet in HCC invasiveness and metastasis To characterize the functions of nMet in HCC, we first encountered the problem in stably expressing nMet in HCC cell lines after several attempts using different expression vectors of nMet and in different HCC cell lines. Due to the possible toxic effect of nMet in cells, we finally established stable clones of nMet in different HCC cell lines using an inducible expression system. The expression of nMet was induced by the addition of doxycycline in culture or in drinking water for the animal. These stable clones with inducible nMet expression were subjected to various in vitro and in vivo functional assays. This objective was successfully addressed. 3. To delineate the molecular pathways of nMet in HCC To delineate the molecular pathways of nMet in HCC, we tested the effect of nMet on various reporter systems. We identified NF-kB as the downstream pathway provoked by nMet. Furthermore, we also identified TAK1 as the intermediate molecular player between nMet and NF-kB. To test whether the functional effect of nMet is driven by TAK1/NF-kB pathway, expression of NF-kB and TAK1 was suppressed in nMet overexpressing cells. The knockdown cells were then subjected to various functional assays. This objective was successfully addressed.
Summary of objectives addressed:
Objectives Addressed Percentage achieved
1.To evaluate the clinicopathological relevance and prognostic significance of nMet in HCCYes100%
2.To characterize the functional role of nMet in HCC invasiveness and metastasisYes100%
3.To delineate the molecular pathways of nMet in HCCYes100%
Research Outcome
Major findings and research outcome: 1. To evaluate the clinicopathological relevance and prognostic significance of nMet in HCC Using immunohistochemistry, our findings revealed intense nMet staining in 89.3% (92/103) of HCC tissues but weak staining in all corresponding non-tumorous livers. Overall nMet expression was significantly higher in tumorous tissues than in corresponding non-tumorous tissues (P < 0.0001). We also observed a progressive increase in nMet expression during the development of HCC from non-tumorous livers with chronic hepatitis (17.0%) and cirrhosis (17.4%) as well as early HCC (30.1%) and advanced HCC (40.6%). Elevated nMet level was significantly correlated with the presence of venous invasion (P = 0.029). Herein, we have provided the first evidence about the presence of nMet in HCC (ECC 2013; AACR 2014). 2. To characterize the functional role of nMet in HCC invasiveness and metastasis The functional assays showed that the induced nMet expression significantly promoted HCC cell growth and anchorage independent growth. It also significantly augmented HCC cell migration and invasiveness. In animal model of subcutaneous injection and orthotopic liver implantation, induced expression of nMet enhanced tumor formation in liver and distant metastasis to lungs. This finding suggests a pivotal role of nMet in HCC tumorigenesis (HKICC 2014). 3. To delineate the molecular pathways of nMet in HCC Out study revealed that nMet activated NF-κB pathway. In the stable clones of nMet, expressions of phospho-p65 and phospho-IKKbeta were enhanced when compared with the vector control cells. In addition, we found that nMet upregulated TAK1 mRNA and protein level leading to the activation of NF-kB pathway. Taken together, our study identify TAK1/NF-kB pathway as the molecular basis underlying the functional activity of nMet (AACR 2015, APASL 2016).
Potential for further development of the research
and the proposed course of action:		 In the continual study of nMet, we are interested to investigate involvement of NF-kB downstream targets in the functional role of nMet. We will examine the expressions and activities of the putative downstream targets of NF-kB in the stable clones of nMet. Besides, we are also interested to study how nMet promotes distant metastasis to lungs. Our preliminary data showed that exosomes derived from nMet stable clones enhanced the migratory and invasive potentials of HCC cells as well as metastasis to lungs from liver primary tumor in mice injected with exosomes prior to orthotopic liver implantation. The role of exosomes in the modulation of tumor microenvironment in lung tissues will be explored.
Layman's Summary of
Completion Report:		 Our study focuses on the study of nuclear Met in liver cancer. Met receptor is found on the cell surface which functions as sensors to receive external signals on the cell surface and transmit the signal into the cells. Our study however has provided data to show that Met exists in the nucleus of liver cancer cells. Our results showed that nuclear Met has a higher expression level in liver cancer cells than the corresponding non-tumorous liver tissues. Higher nuclear Met expression is associated with a poorer survival rate than patients with lower nuclear Met expression. Our findings suggest that the expression of nMet may have prognostic value in liver cancer. In addition, our functional characterization studies showed that nuclear Met promotes liver cancer cell growth and motility in cell culture whereas enhances tumor formation and metastasis in animal model. We also addressed the mechanistic pathway underlying the promoting activity of nuclear Met. This information gained contributes to the understanding of the development of liver cancer.
Research Output
Peer-reviewed journal publication(s)
arising directly from this research project :
(* denotes the corresponding author)
Year of
Publication		 Author(s) Title and Journal/Book Accessible from Institution Repository
2017 Tey SK, Tse EYT, Mao XW, Ko ECF, AST Wong, Lo RCL, Ng IOL, Yam JWP*  Nuclear Met promotes hepatocellular carcinoma tumorigenesis and metastasis by upregulation of TAK1 and activation of NF-κB pathway. Cancer Letters 411:150-161.  No 
Recognized international conference(s)
in which paper(s) related to this research
project was/were delivered :
Month/Year/City Title Conference Name
April 2015, Philadelphia Overexpression of nuclear Met activates NF-kB signaling to promote tumorigenesis and metastasis in hepatocellular carcinoma  2015 American Association for Cancer Research Annual Meeting 
Oct 2014, Hong Kong Nuclear Met is overexpressed and promotes tumorigenesis and metastasis in hepatocellular carcinoma  21st Hong Kong International Cancer Congress 
April 2014, San Diego Role of nuclear Met in hepatocellular carcinoma  2014 American Association for Cancer Research Annual Meeting 
September 2013, Amsterdam Clinical relevance and functional role of nuclear Met in hepatocellular carcinoma  The European Cancer Congress 2013 
February 2016, Tokyo, Japan Nuclear Met regulates liver cancer metastasis via NF-kB/MMP2 pathway.  25th Conference of the Asian Pacific Association for the Study of the Liver (APASL2016) 
June 2016, Korea Clinical relevance and functional role of nuclear Met in hepatocellular carcinoma  The Liver Week 2016 "Next wave in hepatology" 
Other impact
(e.g. award of patents or prizes,
collaboration with other research institutions,
technology transfer, etc.):		 Awards: Tey Sze Keong, a PhD student who involved in this project was awarded the following awards for his oral presentation on this funded project. 1. Best Presentation Award, Department of Pathology, July 2013 2. Best Presentation Award, 19th Research Postgraduate Symposium, Faculty of Medicine, HKU, Nov 2014 3. Graduate students travel scholarship, Tigris Educational Fund, March 2015 4. Travel award, The Liver Week 2016 “Next wave in hepatology” June 16-18, Korea His PhD thesis was graded as outstanding (top 5%) by the examiners. Collaboration: Dr. Yam (PI) and Dr. Alice Wong (co-I) has established research collaboration not only on this funded GRF, but also on research work related to Met signaling in different cancer models. They published collaborative work and succeeded in securing other GRFs entitled “Exosomes released from nuclear Met expressing cells promote liver cancer metastasis and formation of lung premetastatic niche” and “Soluble E-cadherin: a novel molecule regulating angiogenesis?”
  SCREEN ID: SCRRM00542