Research topic: Anti-cancer compounds from natural products

Dr. LU Jin-Jian is now an Associate Professor of Pharmacology in University of Macau. He mainly focuses on screening of natural compounds with anti-cancer potential and exploration of the molecular mechanisms. He is also interested in studying the new targets and strategies for cancer therapy. To present, Dr. Lu has published more than 150 scientific papers in the SCI journals (Citations 5000+, H-index 37). He was awarded as the 2nd Prize of Natural Science: Macao Science and Technology Awards twice and CNPHARS Annual Young Pharmacologists in 2016.

Title: In vitro antitumor effect of cucurbitacin E on human lung cancer cell line and its molecular mechanism
[Abstract] Cucurbitacin E (CuE) is previously reported to exhibit antitumor effect by several means. In this study, CuE acted as a tyrosine kinase inhibitor interfering with the epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) signaling pathway and subsequently induced apoptosis and cell cycle arrest in non-small-cell lung cancer (NSCLC) cell line A549. The apoptosis regulators, cleaved Caspases-3 and Caspases-9, were observed to be increased with the treatment of CuE. The activated transcription factor STAT3 and the apoptosis inhibitor protein survivin were also observed to be reduced. The cell cycle regulators, CyclinA2, cylinB1, CyclinD1 and CyclinE, were also investigated and the results suggested that the cell cycle was arrested at G1/G0 phase. Treatment of CuE also altered the existence status of most of the participants in the EGFR/MAPK signaling. Phosphorylation of EGFR enhanced significantly, leading to the alteration of members downstream, either total amount or phosphorylation level, notably, MEK1/2 and ERK1/2. Moreover, the results of molecular simulation brought an insight on the interaction mechanism between CuE and EGFR. In summary, CuE exhibited anti-proliferative effect against A549 cells by targeting the EGFR/MAPK signaling pathway.

Title: GL-V9 reverses adriamycin resistance in hepatocellular carcinoma cells by affecting JNK2-related autophagy
[Abstract] Adriamycin resistance in HCC seriously hinders the treatment of patients, it is necessary to investigate the mechanisms. Autophagy is involved in adriamycin resistance and JNK2 is related to autophagy. However, whether JNK2 inducing drug resistance though autophagy is unknown. GL-V9, a new synthesized flavonoid derivative, has been proved of its anti-tumor effects. The aim of the study is to explore the role of JNK2-related autophagy on adriamycin-induced drug resistance and the effects of GL-V9 on reversing adriamycin resistance. We concluded that JNK2 played an important role in drug resistance induced by adriamycin. The high expression of JNK2 activated protective autophagy in Hep G2-DOXR cells under non-stress condition, which protected cells from drug attacking. Furthermore, we found that GL-V9 reversed adriamycin resistance by blocking the JNK2-related protective autophagy in HCC.

Title: Panax notoginseng saponins prevent colitis-associated colorectal cancer development: the role of gut microbiota
[Abstract] Gut microbiota dysbiosis is a risk factor for colorectal cancer (CRC) in inflammatory bowel disease (IBD). In this study, the effects of Panax notoginseng saponins (PNS) on colitis-associated CRC progression were evaluated on an azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model. In vivo, PNS significantly relieved AOM/DSS-induced colon tumorigenesis and development by reducing the disease activity index (DAI) scores and colon tumor load. The 16S rRNA data of fecal samples showed that the microbiome community was obviously destructed, while PNS could recover the richness and diversity of gut microbiota. Especially, PNS could increase the abundance of Akkermansia spp. which was significantly decreased in model group and negatively correlated with the progression of CRC. Moreover, ginsenoside compound K (GC-K) was evaluated on the effects of human CRC cells, which was the main bio-transformed metabolite of PNS by gut microbiota. Our data showed that PNS played important role in the prevention of the progression of CRC, due to their regulation on the microbiome balance and microbial bio-converted product with anti-CRC activity.

Title: The ethyl acetate extraction of Pileostegia tomentella (ZLTE) exerts anti-cancer effects on H1299 cells via ROS-induced canonical apoptosis
[Abstract] Lung cancer is the leading cause of cancer death and the most common malignant tumor, the long-term survival of which has stagnated in the past several decades. Pileostegia tomentella Hand. Mazz is a traditional Chinese medicine called “Zhongliuteng” (ZLT) in the pharmacopeia, which has been proved to possess a potent anti-tumor effect on various cancers. In this study, the effects of ZLT N-butanol extraction (ZLTN) and ZLT ethyl acetate extraction (ZLTE) on the viability of non-small cell lung cancer cell (NSCLC) lines H1299 and A549 were evaluated. Here, we firstly reported that ZLTE significantly inhibited H1299 cells growth without affecting the release of lactate dehydrogenase (LDH). In addition, ZLTE induced caspase-dependent apoptosis in a concentration-dependent manner and increased the expression cleaved-PARP and decreased pro-caspase-3, pro-caspase-7, pro-caspase-8, and pro-caspase-9. Moreover, ZLTE increased the level of cellular reactive oxygen species (ROS) in H1299 cells to lead to apoptosis, which was reversed by N-acetyl-cysteine (NAC). Taken together, our results revealed that ZLTE induced caspase-dependent apoptosis via ROS generation, suggesting that ZLTE is a promising herbal medicine for the treatment of NSCLC.

Title: Nagilactone E increases PD-L1 expression through activation of c-Jun in lung cancer cells
[Abstract] Nagilactone E (NLE), a natural product with anticancer activities, is isolated from Podocarpus nagi. In this study, we reported that NLE increased programmed death ligand 1 (PD-L1) expressions at both protein and mRNA levels in human lung cancer cells, and enhanced its localization on the cell membrane. Mechanistically, NLE increased the phosphorylation and expression of c-Jun, and promoted the localization of c-Jun in the nucleus, while silencing of c-Jun by small interfering RNA (siRNA) reduced NLE-induced PD-L1. Further study showed that NLE activated the c-Jun N-terminal kinases (JNK), the upstream of c-Jun, and its inhibitor SP600125 reversed the NLE-increased PD-L1. Moreover, NLE-induced PD-L1 increased the binding intensity of PD-1 on the cell surface. In summary, NLE upregulates the expression of PD-L1 in lung cancer cells through the activation of JNK-c-Jun axis, which has the potential to combine with the PD-1/PD-L1 antibody therapies in lung cancer.