1A-209, 2/F, Block 1, To Yuen Building
+852 3442-2812
+852 3442-0549
jianbyue@cityu.edu.hk
CityU Scholars
Autophagy • Ca²⁺ signalling • Endosomal trafficking • Metastasis • Anticancer immunity • Mitosis • Antiviral

ResearchResearch interests: cell signaling and drug discovery related to autophagy, endosomal trafficking, mitotic kinases/ATPase, and Ca²⁺, in the context of metastasis, anticancer immunity, and virus infection
Currently, several research themes are going on in my laboratory:
Endosomal trafficking in metastasis and anticancer immune response;
the interplay between mitotic kinases and ATPases;
Ca2⁺ signaling in virus infection; and
regulation of autophagy and cell death by Ca⁺ signaling and ROS.
1. Endosomal trafficking in metastasis and anticancer immune responseMetastasis refers to the spread of a tumor from its primary site to other tissues or organs in the body, and it is one of the main causes of the high rate of cancer mortality. Less than 10% of cancer patients die of primary tumors, whereas up to 90% of cancer patients die of tumor metastasis, yet few true anti-metastatic drugs have successfully reached the market. For this reason, it is crucial to fully elucidate the biological regulation mechanisms involved in tumor metastasis in order to develop highly effective anti-metastatic drugs of low toxicity for fighting cancer. Endosomal trafficking is an evolutionally conserved cellular process, which plays an important role in tumor metastasis. We have been developing a new generation of anti-metastatic drugs, which act on endosomal trafficking. We demonstrate that 6-morpholino-1,3,5-triazine derivatives target CapZ to inhibit endosomal trafficking and metastasis (Figure 1) (Oncogene 40, 1775-1791, 2021; Elife in revision). Currently, we are solving the crystal structure of the V1-CapZ complex, and then from the structural information we obtain, we will further optimize the structure of V1 to improve its efficacy and specificity against endosomal trafficking. We will then assess the anti-metastatic activity of newly synthesized V1 analogs either alone or in combination with other chemotherapeutic agents against breast or lung cancers in various mouse models.

Cancer cells develop different strategies to evade immune destruction. For example, the programmed death 1 (PD-1), one of the critical immune checkpoint proteins in activated T cells, binds to its ligand (PD-L1) in tumor cells to inhibit T cell immunity against tumor cells. Disruption of the PD-L1/PD1 axis using the blocking antibodies against these checkpoint proteins has exhibited significant clinical benefits and durable responses in different cancer types. The success of immune checkpoint inhibitors (ICIs) has revolutionized cancer immunotherapy. Still, only a small portion of the patients respond to ICIs, and some patients develop primary or secondary resistance to them. Therefore, it is crucial to fully elucidate the biological regulation mechanisms involved in anticancer immunity in order to develop highly effective drugs of low toxicity for better harnessing immune system to fight cancer. We demonstrated that plasma membrane PD-L1 is subjected to a constitutive endosomal trafficking process: once internalized, PD-L1 trafficks from early endosomes to either recycling endosomes, or MVBs/late endosomes, then to lysosomes or secreted via exosomes. PD-L1’s endosomal trafficking is Rab5-dependent but independent of the canonical autophagy process. We demonstrated that 6J1 (a potent endosomal trafficking inhibitor synthesized by us) blocked the endosomal trafficking of PD-L to induce its accumulation at endocytic vesicles by activating Rab5. 6J1 not only rendered tumor cells more sensitive to the tumor-killing activity of co-cultured T cells in vitro, but also increased tumor-infiltrating cytotoxic T cells by inducing the secretion of chemokines in the tumor microenvironment in the syngeneic mouse model of mammary carcinoma, melanoma, or lung cancer. Moreover, the combination of 6J1 and the anti-PD-1 antibody significantly improved anticancer immune response when compared to either treatment alone. Taken together, our study indicates that manipulation of endosomal trafficking to change membrane PD-L1 and tumor microenvironment by 6J1 provides a promising means to promote the anticancer immune response in addition to the classical ICIs (Figure 2) (Manuscript submitted). Currently, we are assessing the combinatory effects of 6J1 or its potent analogs with ICI(s) against triple-negative breast cancer (TNBC) patient-derived xenograft (PDX) tumor or TNBC cell line-derived xenografts (CDX) tumor engrafted in humanized mouse models.

2. Plk1 and VCP/p97 in cell cycle regulationMitosis is one of the most intricately orchestrated and spectacular events in cell biology. The progression of the M phase is regulated by a cascade of protein phosphorylation and proteolysis events. Errors in these processes can lead to chromosomal instability or aneuloidy, which is a hallmark of many diseases, including cancer. The polo-like kinase 1(Plk1), one key mitotic kinase, is transiently activated during mitosis. The activation of Plk1 has been implicated in regulating spindle architecture and establishing the timing of unperturbed mitosis. The proper centrosome movement and bipolar spindle architecture are essential for genome stability; however, the mechanism that governs these processes remains elusive.
We demonstrated that Plk1 phosphorylates residue Thr76 in VCP/p97 (an AAA-ATPase), at the centrosome from prophase to anaphase. This phosphorylation process recruits VCP to the centrosome and in this way, it regulates centrosome orientation. VCP exhibits strong co-localization with Eg5 (a mitotic kinesin motor), at the mitotic spindle, and the dephosphorylation of Thr76 in VCP is required for the enrichment of both VCP and Eg5 at the spindle, thus ensuring proper spindle architecture and chromosome segregation. We also showed that the phosphatase, PTEN, is responsible for the dephosphorylation of Thr76 in VCP; when PTEN was knocked down, the normal spread of VCP from the centrosome to the spindle was abolished. Cryo-EM structures of VCPT76A and VCPT76E, which represent dephosphorylated and phosphorylated states of VCP, respectively, revealed that the Thr76 phosphorylation modulates the ATPase activity of VCP by altering the inter-domain and inter-subunit interactions, and ultimately the nucleotide-binding pocket conformation. Collectively, our findings demonstrate that the spatially and temporally regulated dynamic phosphorylation and dephosphorylation switch of VCP-Thr76, mediated by Plk1 and PETN, respectively, participates in centrosome movement and spindle architecture to enable the faithful segregation of chromosomes and hence helps to maintain genome stability (Figure 3). We also found that the pT76-VCP signal in the tumor tissues is much stronger than that in normal tissues, suggesting that the phosphorylation level of Thr76 in VCP might be an indicator for cancer diagnosis. Yet, the tumorigenesis ability of breast cancer cells harboring the VCPT76A mutation is significantly lower than in control cells. RNA-seq analysis performed in tumor tissue harboring the VCPWT or VCPT76A mutation showed that differentially expressed genes are in a cell death cluster and a microenvironment cluster. This tumor suppressor phenotype of the VCPT76A mutation might explain why no mutation on VCP-T76 was identified in cancer patients (Manuscript in revision). We are currently studying the role and mechanism of VCP in regulating plasma membrane PD-L1's stability in tumor cells, and assessing the combinatory effects of VCP inhibitors with ICIs against TNBC PDX tumor engrafted in humanized mouse models.

3. Ca²⁺ signaling in virus infectionWe have been studying the role of Ca²⁺ signaling and autophagy in the infection of RNA viruses. We have developed a high-content image-based assay to screen small chemicals inhibiting (+)ss RNA virus infection, and have identified several compounds related to Ca²⁺ signaling as potent antiviral drugs.
COVID-19, caused by SARS-CoV-2 infection, has already disrupted the whole world, and ACE2 is the receptor that mediates the entry of SARS-CoV-2 into host cells. We found that berbamine, a bis-benzylisoquinoline alkaloid, prevented the entry of SARS-CoV-2 pseudoviruses into host cells, and also inhibited genuine SARS-CoV-2 infection. Mechanistically, we showed that berbamine inhibited TRPMLs (Ca²⁺ permeable non-selective cation channels in endosomes and lysosomes), to compromise the endolysosomal trafficking of ACE2. This led to the increased secretion of ACE2 via extracellular vesicles (EVs), and the decrease in the levels of ACE2 at the plasma membrane. Consistently, TRPMLs knockdown resulted in the decrease in the levels of ACE2 at plasma membrane and the concomitant increase in its levels in EVs. Moreover, TRPMLs knockdown inhibited the infection of SARS-CoV-2 in host cells. In summary, these results indicate that berbamine inhibits SARS-CoV-2 infection by compromising TRPMLs-mediated endolysosomal trafficking of ACE2 (Signal Transduct Target Ther. 6: 168, 2021).
Flaviviruses such as dengue virus (DENV), Zika virus (ZIKV), and Japanese encephalitis virus (JEV), are among the leading causes of human and animal infectious diseases in the world, but so far, no effective antiviral agents are available to treat these infections. We found that berbamine and its analogs potently inhibited the infections of JEV, ZIKV, or DENV in vitro by blocking viral entry. Berbamine protected mice from a lethal challenge of JEV as well. Mechanistically, we showed that knockdown of low-density lipoprotein receptor (LDLR) significantly inhibited JEV infection by blocking its entry, and LDLR interacted with the envelope protein of JEV. Berbamine markedly decreased the level of LDLR at the plasma membrane by inducing its secretion via extracellular vesicles (EVs). We further demonstrated that berbamine inhibited TRPMLs to compromise the endolysosomal trafficking of LDLR. This led to the increased secretion of LDLR via EVs and the concomitant decrease in its level at the plasma membrane. TRPMLs knockdown also inhibited JEV or ZIKV infections. In summary, these results indicate that compromise of TRPMLs-mediated endolysosomal trafficking of viral receptors (e.g., LDLR) by berbamine or its analogs is an effective strategy to inhibit flavivirus infection (Emerging Microbes & Infections 10: 1257-1271, 2021).
Currently, we are evaluating the anti-SARS-CoV-2 activity of berbamine in human intestinal organoids, and hACE2 transgenic mouse model. Next, we will determine the combinatory effects of berbamine with remdesivir or other antiviral drugs against SARS-CoV-2 both in vitro and in vivo. The ultimate goal is to develop berbamine or its analogs into a novel class of therapeutic agents for the prevention or treatment of not only COVID-19 but also for diseases caused by any newly emerged coronavirus.
4. Regulation of autophagy and cell death by Ca²⁺ signaling and ROSOxidative stress, referring to intracellular reactive oxygen species (ROS) elevated beyond physiological levels, can trigger Ca²⁺ influx via transient potential receptor melastatin-2 (TRPM2), a Ca²⁺-permeable non-selective cation channel, to cause tissue damage. ROS has also been commonly accepted as inducers of autophagy, an essential catabolic degradation process for cell survival. Autophagy, in turn, acts as an important cellular antioxidant pathway to relieve oxidative stress. Yet, whether and how oxidative stress regulates autophagy remains unknown.
We demonstrated that oxidative stress triggers Ca²⁺ influx via TRPM2 to suppress autophagy, rendering cells more vulnerable to death. Moreover, oxidative stress activates Ca²⁺-calmodulin-dependent protein kinase II (CaMKII) at levels of both phosphorylation and oxidation, which is dependent on TRPM2-mediated Ca²⁺ influx. The activated CaMKII then phosphorylates Ser295 on Beclin1. This phosphorylation subsequently decreases the association between Beclin1 and Vps34, but increases the binding between Beclin1 and Bcl2. In addition, we found that oxidative stress activates the TRPM2-CaMKII cascade to further induce intracellular ROS levels, resulting in mitochondria fragmentation, collapse of mitochondria membrane potential, and ultimate cell death. Clinically, overdose of acetaminophen (APAP) is the leading cause of acute liver failure globally. Likewise, we found that APAP overdose activates the ROS-TRPM2-CaMKII signaling to inhibit autophagy, rendering primary hepatocytes more susceptible to death. Inhibiting TRPM2 or CaMKII markedly decreases APAP-induced liver injury in mice. Taken together, our data indicate that the TRPM2-Ca²⁺-CaMKII signaling plays an important role in oxidative stress-induced cell death and tissue damage (Figure 4) (Autophagy 12: 1340-1354. 2016; Biochim Biophys Acta-Mol. Cell Res 1864: 957-967. 2017). These data also clearly establish TRPM2 as one of the molecular entities determining cell autophagic response to oxidative stress. Recently, we have identified several proteins in CaMKII immunocomplexes by combining tandem affinity purification and mass spectrometry (MS) analysis. We are currently determining how oxidative stress activates the TRPM2-CaMKII signaling to regulate these downstream effectors, and studying the role of these downstream effectors in oxidative stress-induced tissue damage, e.g. stoke and myocardial infarction.

Representive PublicationsWang D, Ye Z, Wei W, Yu J, Huang L, Zhang H, Yue J* (2021) Capping protein regulates endocytosis by controlling F-actin density and recruiting RAB5 effectors to early endosomes. eLife (In press).
Xie F, Xu S, Lu Y, Manno S, Won KF, Sun L, Yue J*, Cheng SH* (2021) Metformin accelerates zebrafish heart regeneration by inducing autophagy. npj Regenerative Medicine 6: 62.
Huang L, Li H, Ye Z, Xu Q, Fu Q, Sun W, Qi W*, Yue J* (2021) Berbamine inhibits Japanese Encephalitis virus (JEV) infection by compromising TPRMLs-mediated endolysosomal trafficking of Low-density lipoprotein receptor (LDLR). Emerging Microbes & Infections 10, 1257-1271.
Huang L, Yuen T, Ye Z, Liu S, Zhang G, Chu H*, Yue J* (2021) Berbamine inhibits SARS-CoV-2 infection by compromising TPRMLs-mediated endolysosomal trafficking of ACE2. Signal Transduct Target Ther. 6: 168.
Ye Z, Wang D, He Y, Yu J, Wei W, Chen C, Wang R, Zhang L, Zhang LH, Zhang LR, Le M, Cho W, M Yang, Zhang H, Yue J* (2021) Vacuolin-1 inhibits endosomal trafficking and metastasis via CapZβ. Oncogene 40, 1775-1791.
Guo W, Wang Q, Pan S, Li J, Shu Y, Chen J, Wang Q, Zhang S, Zhang X, Yue J* (2021) The ERK1/2-ATG13-FIP200 signaling cascade is required for autophagy induction to protect renal cells from hypoglycemia-induced cell death. J. Cell. Physiol. 236: 6932-6947.
Shi X, Zhu K, Ye Z, Yue J* (2020) VCP/p97 targets the nuclear export and degradation of p27Kip1 during G1 to S phase transition. FASEB J. 34(4):5193-5207.
Li C, Huang L, Sun W, Chen Y, He M*, Yue J*, Ballard H* (2019) Saikosaponin D potently Inhibits Autophagy to Suppress EV71 infection. Signal Transduct Target Ther. 4:4.
Zhang K, Sun W, Huang L, Zhu K, Zhu L, Wang Q, Lu Y, Zhang HM, Jin H, Zhang LH*, Zhang LR*, Yue J* (2017) Identifying GAPDH as a Novel Cyclic Adenosine Diphosphoribose (cADPR) Binding Protein by Photoaffinity Protein-Ligand Labeling Approach. J Am Chem. Soc. 139:156-170.
Wang Q, Guo W, Hao B, Shi X, Wong C, Hao Q, Cheung HK, Wu WT, Li GR, Lu Y, Yue J* (2016) Mechanistic Study of the Role of TRPM2-Ca2+ Signaling in Oxidative Stress Induced Autophagy Inhibition. Autophagy 12: 1340-1354.
Wei W, Lu Y, Hai B, Zhang K, Wang Q, Miller AL, Zhang LR, Zhang LH, Yue J* (2015) CD38 is Required for Neural Differentiation of Mouse Embryonic Stem Cells by Modulating Reactive Oxygen Species (ROS). Stem Cells 33, 2664-2673.
Lu Y, Dong S, Hao B, Wang Q, Guo W,Cheung KH, Wong C, Wu WT, Markus H, Yue J* (2014) Vacuolin-1 Potently and Reversibly Inhibits Autophagy by Activating Rab5. Autophagy 10, 1895-1905.
Wei W, Sun H, Ting K, Zhang LH, Lee HC, Li G, Yue J* (2012) Inhibition of Cardiomyocyte Differentiation of Mouse Embryonic Stem Cells by CD38/cADPR/Ca2+ Signaling Pathway. J. Biol. Chem. 287, 35599–35611.
Yu P, Zhang Z, Hao B, Zhao Y, Lee HC, Zhang LH, Zhang LR, Yue J* (2012) A Novel Fluorescent Cell Membrane Permeable Caged-cADPR Analogue. J. Biol. Chem. 287, 24774-24783.
Yue J*, Wei W, Lam CM, Zhao YJ, Dong M, Zhang LR, Zhang LH, Lee HC*. (2009) CD38/cADPR/ Ca2+-Pathway Promotes Cell Proliferation and Delays NGF-Induced Differentiation in PC12 Cells. J. Biol. Chem. 284, 29335-29342.
Yue J*, Ferrell JE Jr. (2006) Mechanistic Studies of the Mitotic Activation of Mos. Mol Cell Biol. 26, 5300-5309.
Yue J*, Xiong W, Ferrell JE Jr. (2006) B-Raf and C-Raf are required for Ras-stimulated p42 MAP kinase activation in Xenopus egg extracts. Oncogene, 25, 3307-3315..
Yue J*, Ferrell JE Jr. (2004) Mos Mediates the Mitotic Activation of p42 MAPK in Xenopus Egg Extracts. Curr. Biol. 14, 1581-1586.
* Corresponding author
PatentsA METHOD OF PROMOTING ANTITUMOR OR ANTICANCER IMMUNITY. Provisional application for patent (PCT63/163,221).
USE OF BERBAMINE OR ITS ANALOGUE FOR PREVENTING OR TREATING RNA VIRUS INFECTION. Provisional application for patent (PCT/CN2020/113378).
METHOD OF TREATING METASTATIC CANCER IN A SUBJECT WITH A PROTEIN INHIBITOR. US patent application (US16/937,995).
METHODS OF PREVENTING OR TREATING FLAVIVIRUS INFECTIONS AND METHODS OF INHIBITING THE ENTRY OF FLAVIVIRUS, ENTEROVIRUS OR LENTIVIRUS INTO HOST CELLS. US patent application (#16/559,869, pending).
METHOD OF TREATING METASTATIC CANCER IN A SUBJECT, Application number: 15609184, US and China patent applications (pending).
VACUOLIN-1 AS AN INHIBITOR OF AUTOPHAGY AND ENDOSOMAL TRAFFICKING AND THE USE THEREOF FOR INHIBITING TUMOR PROGRESSION. US patent No: US 9,717,737 B2; European patent No: 15751298.9-1109, and China patents (CPCH1661599P).
Grant SupportsGrants as the Principal Investigator of external grants (total of 24): 8 RGC grants, 1 NSFC-RGC joint grant, 2 NSFC grants, 1 NSFC-HRC-NZ joint grant, 3 ITF grants, and 1 Croucher-CAS grant, etc.
Research Trainees SupervisedCurrent–2 postdoctoral fellows and 4 PhD students
Past–5 postdoctoral fellows, 12 PhD students (6 from HKU and 6 from CityU), 2 Joint PhD students (HKU and Peking University), and 4 MPhil students (HKU)
19 November 2021


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