Plumbagin Restrains Hepatocellular Carcinoma Angiogenesis by Stromal Cell-Derived Factor (SDF-1)/CXCR4-CXCR7 Axis

Recent Advances in RNA Interference-Based Therapy for Hepatocellular Carcinoma: Emphasis on siRNA

Even though RNA treatments were first proposed as a way to change aberrant signaling in cancer, research in this field is currently ongoing. The term "RNAi" refers to the use of several RNAi technologies, including ribozymes, riboswitches, Aptamers, small interfering RNA (siRNA), antisense oligonucleotides (ASOs), and CRISPR/Cas9 technology. The siRNA therapy has already achieved a remarkable feat by revolutionizing the treatment arena of cancers. Unlike small molecules and antibodies, which need administration every three months or even every two years, RNAi may be given every quarter to attain therapeutic results. In order to overcome complex challenges, delivering siRNAs to the targeted tissues and cells effectively and safely and improving the effectiveness of siRNAs in terms of their action, stability, specificity, and potential adverse consequences are required. In this context, the three primary techniques of siRNA therapies for hepatocellular carcinoma (HCC) are accomplished for inhibiting angiogenesis, decreasing cell proliferation, and promoting apoptosis, are discussed in this review. We also deliberate targeting issues, immunogenic reactions to siRNA therapy, and the difficulties with their intrinsic chemistry and transportation.

The effect of CXCL12 on survival outcomes of patients with viral hepatitis-associated hepatocellular carcinoma after hepatectomy

Background

The CXCL12-CXCR4/CXCR7 axis is garnering growing attention. But the comprehension of its function in the progression of HCC remains controversial. The purpose of this study was to investigate the effects of CXCL12 and its receptor on the prognosis of patients with viral hepatitis-associated HCC after hepatectomy.

Methods

A total of 86 patients had been enrolled who had undergone hepatectomy for HCC and followed up to July 31, 2019, and their clinicopathological and follow-up data were recorded. Tumor and peritumoral tissues were obtained to detect the expression of CXCL12, CXCR4, and CXCR7 using immunohistochemistry. Real-time polymerase chain reaction was utilized to detect hepatitis B or C virus loads, while survival analysis was performed using the Kaplan-Meier method. Furthermore, the Cox proportional hazards regression model was employed to analyze the factors affecting the prognosis.

Results

The results revealed that the CXCL12, CXCR4, and CXCR7 expression in tumor tissues was lower than in the corresponding non-tumor tissues in 20.93 %, 22.09 %, and 23.26 % of the patients, respectively, and that only CXCL12 was found to be related to the extrahepatic invasion of HCC. The survival analysis and Cox regression showed that only CXCL12 was associated with the postoperative survival of patients with HCC, and that it was an independent prognostic risk factor in the CXCL12-CXCR4/CXCR7 axis. The CXCL12low group represented shorter progression-free survival and lower overall survival rates. However, the subgroup analysis displayed that the survival difference associated with CXCL12 was only manifested in patients with higher expression of CXCR4 or CXCR7 in HCC, as compared to the surrounding tissues.

Conclusions

Our findings suggest that, when assessing the prognostic significance of CXCL12 in HCC, it is essential to consider the expression level of its receptor. Nevertheless, CXCL12 can potentially serve as a promising prognostic marker for HCC.

Plumbagin Regulates Snail to Inhibit Hepatocellular Carcinoma Epithelial-Mesenchymal Transition in vivo and in vitro

Background/Aims

Plumbagin (PL) has been shown to effe ctively inhibit autophagy, suppressing invasion and migration of hepatocellular carcinoma (HCC) cells. However, the specific mechanism remains unclear. This study aimed to investigate the effect of PL on tumor growth factor (TGF)-β-induced epithelial-mesenchymal transition (EMT) in HCC.

Methods

Huh-7 cells were cultured, and in vivo models of EMT and HCC-associated lung metastasis were developed through tail vein and in situ injections of tumor cells. In vivo imaging and hematoxylin and eosin staining were used to evaluate HCC modeling and lung metastasis. After PL intervention, the expression levels of Snail, vimentin, E-cadherin, and N-cadherin in the liver were evaluated through immunohistochemistry and Western blot. An in vitro TGF-β-induced cell EMT model was used to detect Snail, vimentin, E-cadherin, and N-cadherin mRNA levels through a polymerase chain reaction. Their protein levels were detected by immunofluorescence staining and Western blot.

Results

In vivo experiments demonstrated that PL significantly reduced the expression of Snail, vimentin, and N-cadherin, while increasing the expression of E-cadherin at the protein levels, effectively inhibiting HCC and lung metastasis. In vitro experiments confirmed that PL up-regulated epithelial cell markers, down-regulated mesenchymal cell markers, and inhibited EMT levels in HCC cells.

Conclusion

PL inhibits Snail expression, up-regulates E-cadherin expression, and down-regulates N-cadherin and vimentin expression, preventing EMT in HCC cells and reducing lung metastasis.

Synthesis and Characterization of Plumbagin S-Allyl Cysteine Ester: Determination of Anticancer Activity In Silico and In Vitro

In recent years, derivatives of natural compounds are synthesized to increase the bioavailability, pharmacology, and pharmacokinetics properties. The naphthoquinone, plumbagin (PLU), is well known for its anticancer activity. However, the clinical use of PLU is hindered due to its toxicity. Previous reports have shown that modification of PLU at 5'-hydroxyl group has reduced its toxicity towards normal cell line. In accordance, in the present study, 5'-hydroxyl group of PLU was esterified with S-allyl cysteine (SAC) to obtain PLU-SAC ester. The drug-likeness of PLU-SAC was understood by in silico ADME analysis. PLU-SAC was characterized by UV-visible spectroscopy, mass spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. Molecular docking and dynamics simulation analysis revealed the interaction of PLU-SAC with proteins of interest in cancer therapy such as human estrogen receptor α, tumor protein p53 negative regulator mouse double minute 2, and cyclin-dependent kinase 2. MMGBSA calculation showed the favorable binding energy which in turn demonstrated the stable binding of PLU-SAC with these proteins. PLU-SAC showed apoptosis in breast cancer cell line (MCF-7) by inducing oxidative stress, disturbing mitochondrial function, arresting cells at G1 phase of cell cycle, and initiating DNA fragmentation. However, PLU-SAC did not show toxicity towards normal Vero cell line. PLU-SAC was synthesized and structurally characterized, and its anticancer activity was determined by in silico and in vitro analysis.

Stromal Cell-Derived Factor-1α (SDF-1α) Promotes Growth and Migration of Bone Marrow Stromal Cells (BMSCs) and Gastric Cancer Cells Through Phosphatidylinositol 3-Kinase/AKT (PI3K/Akt) Pathway

SDF-1α activity is closely related to information transmission and cell migration when contributing to lymphatic metastasis in various tumors. Herein, we explored the interaction among SDF-1α, CXCR4 and PI3K/Akt signaling pathway in gastric cancer (GC) and their roles in this disorder. Human GC cells KATO-III and BMSCs were co-cultured without contact. GC cells were transfected with SDF-1α, CXCR4 inhibitor, and PI3K inhibitor. After examining the efficiency of transfection, cell migration was evaluated using Transwell chamber, and expression SDF-1α, CD133, and CXCR4 was determined by RT-qPCR. With transfection rate of 98%, the number of migrated cells reduced upon inhibition of CXCR4 and PI3K. Luciferase activity in 565 nm are high than CXCR4 inhibition group. (p < 0.05). Likewise, up-regulation of SDF-1α increased the expression of SDF-1 (0.825±0.061), CD133 (0.875±0.058), CXCR4 (0.801±0.052), and Akt (0.852±0.062), compared to the blank group, CXCR4 inhibition group and PI3K inhibition group (p < 0.05). Down-regulation of CXCR4 and PI3K, however, decreased the expression insignificantly (p > 0.05). Collectively, up-regulation of SDF-1α activates CXCR4 signaling pathway of BMSCs and stimulates its downstream PI3K/Akt signaling pathway and and increases the expression of CD133, thereby promoting malignant behaviors of GC cells.

Emerging Importance of Chemokine Receptor CXCR4 and Its Ligand in Liver Disease

Chemokine receptors are members of the G protein-coupled receptor superfamily, which together with chemokine ligands form chemokine networks to regulate various cellular functions, immune and physiological processes. These receptors are closely related to cell movement and thus play a vital role in several physiological and pathological processes that require regulation of cell migration. CXCR4, one of the most intensively studied chemokine receptors, is involved in many functions in addition to immune cells recruitment and plays a pivotal role in the pathogenesis of liver disease. Aberrant CXCR4 expression pattern is related to the migration and movement of liver specific cells in liver disease through its cross-talk with a variety of significant cell signaling pathways. An in-depth understanding of CXCR4-mediated signaling pathway and its role in liver disease is critical to identifying potential therapeutic strategies. Current therapeutic strategies for liver disease mainly focus on regulating the key functions of specific cells in the liver, in which the CXCR4 pathway plays a crucial role. Multiple challenges remain to be overcome in order to more effectively target CXCR4 pathway and identify novel combination therapies with existing strategies. This review emphasizes the role of CXCR4 and its important cell signaling pathways in the pathogenesis of liver disease and summarizes the targeted therapeutic studies conducted to date.

Network-Based Analysis Reveals Gene Signature in Tip Cells and Stalk Cells

BACKGROUND

Angiogenesis occurs during various physiological or pathological processes such as wound healing and tumor growth. Differentiation of vascular endothelial cells into tip cells and stalk cells initiates formation of new blood vessels. Tip cells and stalk cells are endothelial cells with different biological characteristics and functions.

OBJECTIVE

The aim of this study was to determine the mechanisms of angiogenesis by exploring differences in gene expression of tip cells and stalk cells.

METHODS

Raw data were retrieved from NCBI Gene Expression Omnibus (GSE19284). Data were reanalyzed using bioinformatics methods that employ robust statistical methods, including identification of differentially expressed genes (DEGs) between stalk and tip cells, weighted gene correlation network analysis (WGCNA), gene ontology and pathway enrichment analysis using DAVID tools, integration of protein-protein interaction (PPI) networks and screening of hub genes. DEGs of stalk and tip cells were grouped as dataset A. Gene modules associated with differentiation of stalk and tip cells screened by WGCNA were named dataset B. Further, we retrieved existing markers of angiogenesis from previous experimental studies on tip and stalk cells which we named dataset C. Intersection of datasets A, B and C was used as a candidate gene. Subsequently, we verified the results applying quantitative polymerase chain reaction (Q -PCR) to our clinical specimen. In general, the Q-PCR results coincide with the majority of the expression profile.

RESULTS

We identified five candidate genes, including ESM1，CXCR4，JAG1，FLT1 and PTK2 and two pathways, including Rap1 signaling pathway and PI3K-Akt signaling pathway in vascular endothelial cells that differentiate into tip cells and stalk cells using bioinformatic analysis.

CONCLUSION

Bioinformatics approaches provide new avenues for basic research in different fields such as angiogenesis. The findings of this study provide new perspectives and basis for the study of molecular mechanisms of vascular endothelial cell differentiation into stalk and tip cells. Genes and pathways identified in this study are potential biomarkers and therapeutic targets for angiogenesis in tumor.

Computational and In Vitro Analysis of Plumbagin's Molecular Mechanism for the Treatment of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignant tumor and the second leading cause of cancer-related death in the world. Plumbagin (PL) is a small molecule naphthoquinone compound isolated from Plumbago zeylanica L. that has important anticancer properties, but its mechanism requires further investigation. In this study, we used a comprehensive network pharmacology approach to study the mechanism of action of PL for the treatment of HCC. The method includes the construction of multiple networks; moreover, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to identify biological processes and signaling pathways. Subsequently, in vitro experiments were performed to verify the predicted molecular mechanisms obtained from the network pharmacology-based analysis. Network pharmacological analysis showed that PL may exert anti-HCC effects by enhancing reactive oxygen species (ROS) production to generate oxidative stress and by regulating the PI3K/Akt and MAPK signaling pathways. In vitro experiments confirmed that PL mainly mediates the production of ROS, regulates the PI3K/Akt and MAPK signaling pathways to promote apoptosis and autophagy, and shows significant therapeutic effects on HCC. In conclusion, our work proposes a comprehensive systems pharmacology approach to explore the potential mechanism of PL for the treatment of HCC.

Anticancer Effects and Mechanisms of Action of Plumbagin: Review of Research Advances

Plumbagin (PLB), a natural naphthoquinone constituent isolated from the roots of the medicinal plant Plumbago zeylanica L., exhibited anticancer activity against a variety of cancer cell lines including breast cancer, hepatoma, leukemia, melanoma, prostate cancer, brain tumor, tongue squamous cell carcinoma, esophageal cancer, oral squamous cell carcinoma, lung cancer, kidney adenocarcinoma, cholangiocarcinoma, gastric cancer, lymphocyte carcinoma, osteosarcoma, and canine cancer. PLB played anticancer activity via many molecular mechanisms, such as targeting apoptosis, autophagy pathway, cell cycle arrest, antiangiogenesis pathway, anti-invasion, and antimetastasis pathway. Among these signaling pathways, the key regulatory genes regulated by PLB were NF-kβ, STAT3, and AKT. PLB also acted as a potent inducer of reactive oxygen species (ROS), suppressor of cellular glutathione, and novel proteasome inhibitor, causing DNA double-strand break by oxidative DNA base damage. This review comprehensively summarizes the anticancer activity and mechanism of PLB.

Functions and mechanisms of chemokine receptor 7 in tumors of the digestive system

Chemokine (C-X-C motif) receptor 7 (CXCR7), recently termed ACKR3, belongs to the G protein-coupled cell surface receptor family, binds to stromal cell-derived factor-1 [SDF-1, or chemokine (C-X-C motif) ligand 12] or chemokine (C-X-C motif) ligand 11, and is the most common chemokine receptor expressed in a variety of cancer cells. SDF-1 binds to its receptor chemokine (C-X-C motif) receptor 4 (CXCR4) and regulates cell proliferation, survival, angiogenesis and migration. In recent years, another new receptor for SDF-1, CXCR7, has been discovered, and CXCR7 has also been found to be expressed in a variety of tumor cells and tumor-related vascular endothelial cells. Many studies have shown that CXCR7 can promote the growth and metastasis of a variety of malignant tumor cells. Unlike CXCR4, CXCR7 exhibits a slight modification in the DRYLAIV motif and does not induce intracellular Ca²⁺ release following ligand binding, which is essential for recruiting and activating G proteins. CXCR7 is generally thought to work in three ways: (1) Recruiting β-arrestin 2; (2) Heterodimerizing with CXCR4; and (3) Acting as a “scavenger” of SDF-1, thus lowering the level of SDF-1 to weaken the activity of CXCR4. In the present review, the expression and role of CXCR7, as well as its prognosis in cancers of the digestive system, were investigated.

Efficacy evaluation and mechanism study on inhibition of breast cancer cell growth by multimodal targeted nanobubbles carrying AMD070 and ICG

To construct targeted nanobubbles carrying both small-molecule CXCR4 antagonist AMD070 and light-absorbing material indocyanine green (ICG), and to study their in vitro multimodal imaging, as well as their mechanism and efficacy of inhibition of breast cancer cell growth. Nanobubbles carrying AMD070 and ICG (ICG-TNBs) were constructed by carbodiimide reaction and mechanical oscillation. The physical characteristics and in vitro multimodal imaging were determined. The binding potential of ICG-TNBs to human breast cancer cells were observed by laser confocal microscopy. CCK-8 and flow cytometry were used to analyze the role of ICG-TNBs + US in inhibiting proliferation and inducing apoptosis of tumor cells. Flow cytometry and Western blotting are used to analyse the ROS generation and molecular mechanisms. ICG-TNBs had a particle size of 497.0 ± 29.2 nm and a Zeta potential of -8.05 ± 0.73 mV. In vitro multimodal imaging showed that the image signal intensity of ICG-TNBs increased with concentration. Targeted binding assay confirmed that ICG-TNBs could specifically bind to MCF-7 cells (CXCR4 positive), but not to MDA-MB-468 cells (CXCR4 negative). CCK-8 assay and flow cytometry analysis showed that ICG-TNBs + US could significantly inhibit the growth of MCF-7 breast cancer cells and promote their apoptosis. Flow cytometry and Western blotting showed that ICG-TNBs + US could significantly raise generation of ROS, reduce the expression of CXCR4, inhibit phosphorylation of Akt, and increase the expression of Caspase3 and Cleaved-caspase3. This indicated that ICG-TNBs could effectively inhibit and block the SDF-1/CXCR4 pathway, thus leading to the apoptosis of MCF-7 cells. ICG-TNBs can specifically bind to CXCR4 positive breast cancer cells, furthermore inhibit growth and promote apoptosis of breast cancer cells combined with ultrasonic irradiation by blocking the SDF-1/CXCR4 pathway. This study introduces a novel concept, method and mechanism for integration of targeted diagnosis and treatment of breast cancer.