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ENQUIRE PROJECT DETAILS BY GENERAL PUBLIC |
| Project Details |
| Funding Scheme : | General Research Fund | ||||||||||||||||
| Project Number : | 17141216 | ||||||||||||||||
| Project Title(English) : | Metadherin: a novel target for b-catenin and a critical mediator of the positive feedback loop between highly metastatic tumor cells and macrophages? | ||||||||||||||||
| Project Title(Chinese) : | Metadherin: 新的β-catenin靶分子能誘導高轉移性腫瘤細胞與巨噬細胞之間的正反饋環路？ | ||||||||||||||||
| Principal Investigator(English) : | Prof Wong, Alice Sze-Tsai | ||||||||||||||||
| Principal Investigator(Chinese) : | |||||||||||||||||
| Department : | School of Biological Sciences | ||||||||||||||||
| Institution : | The University of Hong Kong | ||||||||||||||||
| E-mail Address : | awong1@hku.hk | ||||||||||||||||
| Tel : | 22990865 | ||||||||||||||||
| Co - Investigator(s) : |
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| Panel : | Biology & Medicine | ||||||||||||||||
| Subject Area : | Biological Sciences | ||||||||||||||||
| Exercise Year : | 2016 / 17 | ||||||||||||||||
| Fund Approved : | 1,092,092 | ||||||||||||||||
| Project Status : | Completed | ||||||||||||||||
| Completion Date : | 31-12-2019 | ||||||||||||||||
| Project Objectives : |
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| Abstract as per original application (English/Chinese): |
Metastasis is the cause of >90% cancer deaths, and yet the control of the processes is still poorly understood. Emerging evidences show that interaction between tumors and their microenvironment, but not tumor cells per se, is the key factor that ultimately determines tumor progression and therefore of obvious scientific interest and therapeutic value. In ovarian cancer, a highly metastatic and rapidly lethal tumor, disseminated cancer cells that succeed in infiltrating the peritoneum present the distinct feature of adhering on macrophages, whereas those that unable to coopt also fail to thrive. However, the molecular mechanisms underlying this interaction have not been defined because the lack of tightly controlled, representative cell models. Moreover, traditional bulk measurements to visualize metastasis are unable to differentiate different phenotypes and their kinetics in the same population, masking cell-to-cell variation that is important for therapeutic response. We are the first to relate specific cell adhesion changes to the metastatic potential of ovarian cancer. Recently, we have further successfully developed a new isogenic ovarian cancer model with different metastatic properties, enabling us to unravel key factors mediating metastasis. In our pilot studies, using a live single-cell imaging platform to probe subpopulations and cell-to-cell variability, we show for the first time that HM (highly metastatic), but not NM (non-metastatic) tumor cells, have a selective advantage in activating M1 macrophages to a tumor-associated macrophage (TAM)-like phenotype. In turn, TAMs supported HM tumor cell growth, forming a positive feedback loop. Interestingly, this interaction also significantly increased the ploidy level, which is pivotal for tumor aggressiveness and therapy resistance, in a significant subset of HM. Expression of b-catenin was activated in HM, but not NM, plays a key role in this process through Metadherin. We hypothesize that disseminated ovarian cancer cells expressing Metadherin can survive and progress in macrophage-rich microenvironment via juxtacrine activation of the b-catenin-Metadherin/CEACAM1-CCL3 signaling pathway. In this proposal, we will: (1) elucidate the specific contribution of Metadherin-driven HM on properties of macrophages and how the crosstalk may affect tumorigenic behavior; (2) decipher the molecular mechanism of polyploidization with particular relevance to cytokinesis machinery, mitotic spindle checkpoint, and genome/chromosome stability; and (3) unravel the underlying mechanisms of action of the Metadherin/CEACAM1 juxtacrine loop. This research will provide important new mechanistic insights into the critical step in tumor metastasis, with implications of finding novel treatment options for effective therapies. 癌細胞轉移是多於90％的癌症死亡原因，但我們對於過程的控制仍知之甚少。新證據顯示腫瘤及其微環境之間的相互作用，而非只是腫瘤細胞本身，是最終決定腫瘤進展的關鍵因素。因此，腫瘤微環境有明顯重要的科研價值。卵巢癌是種高轉移性，並迅速致命的腫瘤。成功擴散至腹膜的卵巢癌細胞具有黏附至巨噬細胞的顯著特徵。因缺乏有代表性及嚴謹控制的細胞實驗模型，兩種細胞之間互動的分子機制尚待分析。 此外，細胞的個體差異對治療反應有重要影響。然而，傳統的批量檢測實驗無法區分在同一細胞族群中不同的表型和其動力學。我們是第一個把細胞黏附的特有變化聯繫到卵巢癌的轉移能力。最近，我們成功開發了一個基因同源的卵巢癌自發性轉移模型，使我們能夠從中找出轉移的關鍵因素。在試驗研究中，我們使用實時單細胞成像來探測細胞亞群的變異性。我們首次顯示了HM（高轉移性），而非NM（非轉移性）腫瘤細胞，能把M1型巨噬細胞誘導至腫瘤相關巨噬細胞（TAM）的表型。反過來，TAM支持HM腫瘤細胞的生長，形成一個正反饋環路。有趣的是，這互動過程增加了部份HM 腫瘤細胞的染色體套數，而有非常數染色體的腫瘤細胞已知是有高度侵襲性和抗治療性。β-catenin的表達水平在HM中相對較高，並可能通過Metadherin在此過程中發揮關鍵作用。我們推測播散卵巢癌細胞可以近分泌啟動β-catenin-Metadherin/ CEACAM1-CCL3信號通路，從而存活於有大量巨噬細胞的微環境中。在這個項目中，我們將：（1）研究Metadherin如何驅動HM與巨噬細胞的互動，以及此互動如何影響腫瘤發展; （2）解構HM染色體多倍化的分子機制，並重點分析尤為相關的胞質分裂機械、有絲分裂紡錘體檢查點和基因/染色體穩定性; （3）探討Metadherin/CEACAM1近分泌循環的基本分子機制。這項研究將對腫瘤轉移提供新見解，並為尋找新治療方案帶來特別意義。 |
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| Realisation of objectives: | Objective 1: It is now increasingly clear that the tumor microenvironment, rather than tumor cells per sec, is the key determining factor to tumor progression. However, previous studies have focused mainly on tumor cells, the microenvironment remains poorly understood, especially cells of the immune system, which are the most important regulators in the microenvironment that can affect tumor behavior. Recently, we have developed a new isogenic ovarian cancer model with different metastatic properties to unravel key factors mediating metastasis. HM was unique in its ability to metastasize consistently to the peritoneum, mimicking the major dissemination route of human ovarian cancer. In contrast, NM failed to form detectable metastases although it was equally tumorigenic. Using this well-controlled HM and NM cells and a robust single-cell based time-lapse microscopy, we identified a positive feedback loop between HM and macrophages that is essential to ovarian cancer metastasis. HM, when cocultured with HM-activated macrophages can induce epithelial-to-mesenchymal transition of HM, in which HM changed from a rounded shape to an elongated one, with loss of cell-cell contact and enhancement of migration and invasiveness. Further, depletion of b-catenin or Metadherin inhibited tumor cell aggressiveness induced by TAMs. Tumor xenografts in humanized mice and patients’ clinical samples corroborate these findings in vivo. Percentage achieved: 100% Objective 2: We showed for the first time a direct role of Metadherin-CEACAM1 interaction in polyploidization and protumor phenotype. We provided further evidence that this process involved the activation of cyclin E. It is also clinically relevant that cyclin E was overexpressed in the clinical samples of ovarian cancer patients, in particular in the giant polyploid cells. The abscission checkpoint is known to be dependent on the persistent activity of the Aurora B and Survivin but not Mad2 and BubR1. We further provide evidence that HM could undergo multiple rounds of failed cytokinesis, suggesting that they could tolerant the presence of multiple sets of chromosomes. Percentage achieved: 100% Objective 3: Until now, there has no understanding of the structure of cell surface Metadherin and its binding partner and how their structures might affect their interactions, and the role those interactions in cancer. Using a series of deletion constructs within Metadherin, we identified a fragment of amino acid residues 75-582 harbors the essential region required for interaction with CEACAM1. In search of the underlying mechanism of how b-catenin may regulate Metadherin, putative TCF binding sites were found in the promoter of Metadherin, and p300, a coactivator of b-catenin/TCF-mediated transcription was involved. Our studies also revealed a previously unrecognized role of b-catenin in the downregulation of multiple microRNAs through attenuating microRNA biogenesis. CEACAM1 transduces a STAT3 metastatic signaling to regulate CCL3. These results uncover new regulatory mechanisms that may control the high degree of aggressiveness and potential for metastasis that are characteristic of ovarian cancer. Percentage achieved: 100% These findings not only reveal a previously unrecognized role for HM tumor cells as TAM activators, but also unveil a novel role for HM and macrophages in mediating the metastatic cascade through a positive feedback loop, which provide new perspectives on tumor cell and microenvironment interaction in the peritoneum, and that its targeting may represent a potential therapeutic advantage for metastatic ovarian cancer. Publications (*, corresponding author) (Note: ALL as corresponding author): Journal article: 1. To SK, Tang MK, Ip PC, Shi J, and Wong AS* Live single-cell imaging reveals a polyploid tumor cell subset upon bidirectional tumor-macrophage interaction. Nat. Cell Biol. (under review). 2. Li SS, Ma J, and Wong AS* (2018) Chemoresistance in ovarian cancer: exploiting cancer stem cell metabolism. J. Gynecol. Oncol. 29: e32 [invited] (impact factor: 3.140). 3. To SK, Mak AS, Fung YM, Che CM, Li SS, Deng W, Ru B, Zhang J, and Wong AS* (2017) b-catenin downregulates Dicer to promote ovarian cancer metastasis. Oncogene 36: 5927-5938 (impact factor: 7.219). Conference proceedings: 4. To SK, Shi J, and Wong AS* (2021) b-catenin in metastatic ovarian cancer cells mediates polyploidy induced by tumor-associated macrophages. American Association for Cancer Research Annual Meeting (Abstract No. 21-A-2463-AACR). 5. To SK, Zeng JZ, and Wong AS* (2017) Targeting b-catenin signaling for anti-metastasis therapies. Asian Federation for Pharmaceutical Sciences Conference, Xiamen, China [Invited]. 6. Wong AS* (2017) Ovarian cancer metastasis and the metastatic niche. Korean Gynecologic Cancer Registry 2017 Meeting, Seoul, Korea [Special Lecture]. | ||||||||||||||||
| Summary of objectives addressed: |
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| Research Outcome | |||||||||||||||||
| Major findings and research outcome: | Objective 1: Here, using both an isogenic ovarian cancer cell line model with opposite metastatic abilities and humanized mice, we show that highly metastatic (HM) cells, but not non-metastatic (NM) cells, have a selective advantage in skewing the interacting macrophages to tumor-associated macrophages (TAM). Live single-cell imaging reveals that these TAMs subsequently induce failed cytokinesis in a significant subset of HM, leading to the formation of polyploid tumor cells that are pivotal for tumor aggressiveness. This bidirectional interaction between HM and macrophages are mediated by Metadherin expression induced by b-catenin on HM via trans-acting CEACAM1 expressed on macrophages. Moreover, HM-macrophage interaction promotes macrophage secretion of the cytokine CCL3. Tumor xenografts in humanized mice and patients’ clinical samples corroborate these findings in vivo. Publication: Journal article: #1 Conference proceeding: #4-6 Objective 2: We show for the first time that this process involves the activation of cyclin E. It is also clinically relevant that cyclin E is overexpressed in the clinical samples of ovarian cancer patients, in particular in the giant polyploid cells. The abscission checkpoint is known to be dependent on the persistent activity of the Aurora B and Survivin. We also observed the presence of chromosome bridge in the co-cultured HM, which may be a trigger for cytokinesis failure. HM cells could tolerant the presence of multiple sets of chromosomes. Publication: Journal articles: #1 Conference proceeding: #4 Objective 3: On exploring how the Metadherin interacts with CEACAM1, we show that this is mediated through a direct binding at positions of amino acid residues 75-582. Furthermore, we uncovered a new link of b-catenin, Dicer, a key component of the microRNA-processing machinery, and Metadherin activation. Moreover, we also show that CEACAM1 can transduce a STAT3 metastatic signaling cascade to activate CCL3, a strong chemoattractant for monocytes. These findings not only shed new light on the significance of considering tumor cells as heterogeneous populations in cancer progression, but also emphasize the need of a population-informed framework in the development of therapeutics. Publication: Journal article: #1, 3 Conference proceedings: #4-6 Taken together, our data strongly support the important role for a b-catenin/Metadherin/CEACAM1 cascade in mediating a novel positive feedback between macrophages and a subpopulation of cancer cells that is essential for ovarian cancer metastasis and provide a mechanistic rationale for targeting b-catenin or its associated signaling in the treatment of this unique metastatic population. Publication: Journal article: #2 Conference proceedings: #4-6 | ||||||||||||||||
| Potential for further development of the research and the proposed course of action: |
We reveal the novel identification of a polyploid metastatic tumor cell subset that has a pivotal role in the metastatic heterogeneity, aggressiveness, and therapy resistance of ovarian cancer. This reveals a new direction for understanding the regulatory mechanism of polyploidization in ovarian cancer metastasis and implicate that targeting b-catenin/Metadherin could provide a promising therapeutic opportunity to target this unique metastatic subpopulation. Our findings underscore a critical role for b-catenin/Metadherin during the development and maintenance of the polyploid cells. While Metadherin was reported to localize in cellular compartments such as nucleus and endoplasmic reticulum, we showed the cell surface localization of Metadherin. The binding partner of surface Metadherin is unknown, and we identified a functional interaction of Metadherin and CEACAM1. Intriguingly, we found high b-catenin is associated with high Metadherin expression in patients’ samples of ovarian cancer tissues. We also found polyploid cancer cells in ascitic cells collected from ovarian cancer patients’ ascites. We are actively pursuing in this direction to document such effect using more extensive clinicopathological studies. Given that targeting phenotypic heterogeneity is evolving as an important therapeutic concept, it is of great interest to identify the key signaling path in this process. Peritoneal metastasis has also been detected in patients with breast, gastric, and colon cancer. To expand our understanding of the bidirectional tumor-macrophage interaction in polyploidization, we plan to examine if this crosstalk is also seen in other tumor types in which peritoneal metastasis is an important pathological process. We will also examine the level and effect of tumor-macrophage interaction in healthy donors or non-cancerous patients. These findings should highlight the functional importance of tumor-macrophage interaction in impacting malignant cell behavior and implies important clinical implications. | ||||||||||||||||
| Layman's Summary of Completion Report: | One of the greatest unmet needs compromising the successful treatment of cancer is metastasis. A critical, rate-limiting step of metastasis is the ability of less than 0.01% disseminated cancer cells to survive and settle in target tissue, which involves specific tumor-host interaction. The observation that those which fail to coopt to the microenvironment also fail to thrive further suggests the importance of the tumor-host interaction. Unraveling the intricate details of this particular crosstalk is of obvious importance. Our new findings of this project indicate that the bidirectional tumor-macrophage interaction is a pivotal regulator of polyploidization and that it could be a promising target. (i) We show for the first time a preferential activation of the macrophages by the metastatic-competent than the metastatic-incompetent cancer cells. (ii) We uncover a new uncommon genetically unstable polyploid metastatic subset upon this interaction. (iii) We also present evidence that this activation is mediated by a juxtacrine b-catenin/Metadherin/CEACAM1-CCL3 signaling axis. These results reveal a new direction for understanding the regulatory mechanisms of polyploidization and highlight b-catenin/Metadherin as a viable therapeutic target. Targeting b-catenin/Metadherin may thus be a useful approach to decrease this aggressive and therapy resistant subpopulation, the most distressing complication for successful treatment. | ||||||||||||||||
| Research Output | |||||||||||||||||
| Peer-reviewed journal publication(s) arising directly from this research project : (* denotes the corresponding author) |
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| Recognized international conference(s) in which paper(s) related to this research project was/were delivered : |
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| Other impact (e.g. award of patents or prizes, collaboration with other research institutions, technology transfer, etc.): |
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| SCREEN ID: SCRRM00542 |