Molecular-Scale Investigations Reveal the Effect of Natural Polyphenols on BAX/Bcl-2 Interactions.

Apoptosis signaling controls the cell cycle through the protein-protein interactions (PPIs) of its major B-cell lymphoma 2-associated x protein (BAX) and B-cell lymphoma 2 protein (Bcl-2). Due to the antagonistic function of both proteins, apoptosis depends on a properly tuned balance of the kinetics of BAX and Bcl-2 activities. The utilization of natural polyphenols to regulate the binding process of PPIs is feasible. However, the mechanism of this modulation has not been studied in detail. Here, we utilized atomic force microscopy (AFM) to evaluate the effects of polyphenols (kaempferol, quercetin, dihydromyricetin, baicalin, curcumin, rutin, epigallocatechin gallate, and gossypol) on the BAX/Bcl-2 binding mechanism. We demonstrated at the molecular scale that polyphenols quantitatively affect the interaction forces, kinetics, thermodynamics, and structural properties of BAX/Bcl-2 complex formation. We observed that rutin, epigallocatechin gallate, and baicalin reduced the binding affinity of BAX/Bcl-2 by an order of magnitude. Combined with surface free energy and molecular docking, the results revealed that polyphenols are driven by multiple forces that affect the orientation freedom of PPIs, with hydrogen bonding, hydrophobic interactions, and van der Waals forces being the major contributors. Overall, our work provides valuable insights into how molecules tune PPIs to modulate their function.

Investigating the crosstalk between chronic stress and immune cells: implications for enhanced cancer therapy.

Chronic stress has a substantial influence on the tumor microenvironment (TME), leading to compromised effectiveness of anti-cancer therapies through diverse mechanisms. It disrupts vital functions of immune cells that play a critical role in anti-tumor immunity, such as the inhibition of dendritic cells (DCs) and lymphocytes, while simultaneously enhancing the activity of immune cells that support tumor growth, such as myeloid-derived suppressor cells and tumor-associated macrophages. Furthermore, chronic stress exerts a significant impact on crucial mechanisms within the TME, including angiogenesis, DNA repair, hypoxia, extracellular matrix deposition, and tumor metabolism. These alterations in the TME, induced by stress, result from the activation of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system, in conjunction with epigenetic modifications. In conclusion, chronic stress significantly influences the TME and impedes the efficacy of anti-cancer treatments, underscoring the importance of targeting stress pathways to improve therapeutic results.

Single-molecule scale quantification reveals interactions underlying protein-protein interface: from forces to non-covalent bonds.

Protein-protein interactions (PPIs) between the B-cell lymphoma 2 (Bcl-2) family are considered a major driving force in cell cycle regulation and signaling. However, how this interfacial noncovalent interaction is achieved molecularly remains poorly understood. Herein, anti-apoptotic protein (Bcl-2) and pro-apoptotic protein (BAX) were used as models and their PPIs were explored for the first time using atomic force microscopy-based single-molecule force spectroscopy (SMFS) and in silico approaches. In addition, we used advanced analytical models, including multiple kinetic models, thermodynamic models, Poisson distributions, and contact angle molecular recognition to fully reveal the complexity of the BAX/Bcl-2 interaction interfaces. We propose that the binding kinetics between BAX/Bcl-2 are mainly mediated by specific (hydrogen bonding) and non-specific forces (hydrophobic interactions and electrostatic interactions) and show that the complicated multivalent binding interaction induces stable BAX/Bcl-2 complexes. This study enriches our understanding of the molecular mechanisms by which BAX interacts with Bcl-2. It provides valuable insights into the physical factors that need to be considered when designing PPI inhibitors.

Effect of various hepatectomy procedures on circulating tumor cells in postoperative patients: a case-matched comparative study.

Background: The objective of this study is to elucidate the prevalence of systemic circulating tumor cells (CTCs) prior to and following resection of hepatocellular carcinoma (HCC), and to compare the disparities in postoperative CTCs in terms of quantity and classifications between the open liver resection (OPEN) and laparoscopic liver resection (LAP) cohorts. Patients materials and methods: From September 2015 to May 2022, 32 consecutive HCC patients who underwent laparoscopic liver resection at Southwest Hospital were retrospectively enrolled in this study. The clinicopathological data were retrieved from a prospectively collected computer database. Patients in the OPEN group matched at a 1:1 ratio with patients who underwent open liver resection during the study period on age, gender, tumor size, number of tumors, tumor location, hepatitis B surface antigen (HBsAg) positivity, alpha-fetoprotein (AFP) level, TNM and Child-Pugh staging from the database of patients to form the control group. The Can-Patrol CTC enrichment technique was used to enrich and classify CTCS based on epithelial-mesenchymal transformation phenotypes. The endpoint was disease-free survival (DFS), and the Kaplan-Meier method and multiple Cox proportional risk model were used to analyze the influence of clinicopathological factors such as total CTCs and CTC phenotype on prognosis. Results: The mean age of the 64 patients with primary liver cancer was 52.92 years (23-71), and 89.1% were male. The postoperative CTC clearance rate was more significant in the OPEN group. The total residual CTC and phenotypic CTC of the LAP group were significantly higher than those of the OPEN group (p = 0.017, 0.012, 0.049, and 0.030, respectively), which may increase the possibility of metastasis (p = 0.042). In Kaplan-Meier analysis, DFS was associated with several clinicopathological risk factors, including Barcelona Clinical Liver Cancer (BCLC) stage, tumor size, and vascular invasion. Of these analyses, BCLC Stage [p = 0.043, HR (95% CI) =2.03(1.022-4.034)], AFP [p = 0.007, HR (95% CI) =1.947 (1.238-3.062)], the number of positive CTCs [p = 0.004, HR (95% CI) =9.607 (2.085-44.269)] and vascular invasion [p = 0.046, HR (95% CI) =0.475 (0.22-1.023)] were significantly associated with DFS. Conclusion: In comparison to conventional OPEN technology, LAP technology has the capacity to augment the quantity of epithelial, mixed, and mesenchymal circulating tumor cells (CTCs). Following the surgical procedure, there was a notable increase in the total CTCs, epithelial CTCs, and mixed CTCs within the LAP group, indicating a potential drawback of LAP in facilitating the release of CTCs.

Mechanism of multidrug resistance to chemotherapy mediated by P­glycoprotein (Review).

Multidrug resistance (MDR) seriously limits the clinical application of chemotherapy. A mechanism underlying MDR is the overexpression of efflux transporters associated with chemotherapeutic drugs. P­glycoprotein (P­gp) is an ATP­binding cassette (ABC) transporter, which promotes MDR by pumping out chemotherapeutic drugs and reducing their intracellular concentration. To date, overexpression of P­gp has been detected in various types of chemoresistant cancer and inhibiting P­gp­related MDR has been suggested. The present review summarizes the mechanisms underlying MDR mediated by P­gp in different tumors and evaluated the related signaling pathways, with the aim of improving understanding of the current status of P­gp­mediated chemotherapeutic resistance. This review focuses on the main mechanisms of inhibiting P­gp­mediated MDR, with the aim of providing a reference for the study of reversing P­gp­mediated MDR. The first mechanism involves decreasing the efflux activity of P­gp by altering its conformation or hindering P­gp­chemotherapeutic drug binding. The second inhibitory mechanism involves inhibiting P­gp expression to reduce efflux. The third inhibitory mechanism involves knocking out the ABCB1 gene. Potential strategies that can inhibit P­gp include certain natural products, synthetic compounds and biological techniques. It is important to screen lead compounds or candidate techniques for P­gp inhibition, and to identify inhibitors by targeting the relevant signaling pathways to overcome P­gp­mediated MDR.

Clinico-characteristics of patients which correlated with preferable treatment outcomes in immunotherapy for advanced hepatocellular carcinoma: a systematic review and meta-analysis.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is the third-most lethal malignant tumor worldwide. The rapid development of immunotherapy utilizing immune checkpoint inhibitors for advanced HCC patients has been witnessed in recent years, along with numerous randomized clinical trials demonstrating the survival benefits for these individuals. This systematic review and meta-analysis aimed to identify specific clinico-pathological characteristics of advanced HCC patients that may lead to preferable responses to immunotherapy in terms of overall survival (OS), progression-free survival (PFS), and objective response rate (ORR). METHODS: The included clinical trials were retrieved from PubMed, Embase, the Cochrane library, and the Web of Science databases published in English between 1 January 2002 and 20 October 2022. A systematic review and meta-analysis for first-line and second-line phase II/III studies were conducted on immunotherapy for patients with advanced HCC by using OS as the primary outcome measure, and PFS and ORR as the secondary outcome measures to obtain clinico-pathological characteristics of patients which might be preferable responses to programmed death-1 (PD-1) and programmed cell death-Ligand 1 (PD-L1) inhibitors. Toxicity and specific treatment-related adverse events (TRAEs) were also determined. RESULTS: After screening 1392 relevant studies, 12 studies were included in this systematic review and meta-analysis to include 5948 patients. Based on the analysis of interaction, the difference in OS after first-line immunotherapy between the subgroups of viral hepatitis [hazard ratio (HR)=0.73 vs 0.87, P for interaction=0.02] and macrovascular invasion and/or extrahepatic spread (HR=0.73 vs 0.89, P for interaction=0.02) were significant. The difference in PFS between the subgroups of viral hepatitis was highly significant (pooled HR=0.55 vs 0.81, P for interaction=0.007). After second-line immunotherapy, the difference in ORR between the subgroups of Barcelona Clinic Liver Cancer was significant (pooled ES=0.12 vs 0.23, P for interaction=0.04). Compared with PD-L1 inhibitors, PD-1 inhibitors may have a higher probability to cause TRAEs. Diarrhea, increased aspartate aminotransferase, and hypertension were the top three TRAEs. CONCLUSIONS: This systematic review and meta-analysis represents the first pilot study aimed at identifying crucial clinico-pathological characteristics of patients with advanced HCC that may predict favorable treatment outcomes in terms of OS, PFS, and ORR to immunotherapy. Findings suggest that patients with viral hepatitis positivity (especially hepatitis B virus) and macrovascular invasion and/or extrahepatic spread may benefit more in OS when treated with PD-1/PD-L1 immune checkpoint inhibitors.

Open Radiofrequency Ablation Combined with Splenectomy and Pericardial Devascularization vs. Liver Transplantation for Hepatocellular Carcinoma Patients with Portal Hypertension and Hypersplenism: A Case-Matched Comparative Study.

AIM: To compare the short- and long-term treatment outcomes of open radiofrequency ablation combined with splenectomy and pericardial devascularization versus liver transplantation for hepatocellular carcinoma patients with portal hypertension and hypersplenism. METHODS: During the study period, the treatment outcomes of consecutive HCC patients with portal hypertension and hypersplenism who underwent open radiofrequency ablation, splenectomy and pericardial devascularization (the study group) were compared with the treatment outcomes of a case-matched control group of HCC patients who underwent liver transplantation. RESULTS: The study group consisted of 32 patients, and the control group comprised 32 patients selected from 155 patients who were case-matched by tumor size, age, gender, MELD sore, tumor location, TNM classification, degree of splenomegaly and Child-Pugh staging. Baseline data on preoperative laboratory tests and tumor characteristics were comparable between the two groups. The mean follow-up was 43.2 ± 5.3 months and 44.9 ± 5.8 months for the study and control groups, respectively. Although the disease-free survival rates of the control group were better than those of the study group (P < 0.001), there was no significant difference in the cumulative overall survival time or the incidence of portal vein thrombosis between the two groups (P = 0.670, 0.083). Compared with the control group, the study group had significantly less intraoperative blood loss, and lower incidences of postoperative pleural effusion and pneumonia (all P < 0.05). CONCLUSION: Open radiofrequency ablation, splenectomy and pericardial devascularization for small HCCs with portal hypertension and hypersplenism can be an alternative therapy for a subset of carefully selected patients under the shortage of liver donors.

Molecular Mechanisms of Resistance to Tyrosine Kinase Inhibitors Associated with Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death, which can be attributed to the high incidence and first diagnosis at an advanced stage. Tyrosine kinase inhibitors (TKIs), a class of small-molecule targeting drugs, are primarily used for the clinical treatment of HCC after chemotherapy because they show significant clinical efficacy and low incidence of clinical adverse reactions. However, resistance to sorafenib and other TKIs, which can be used to treat advanced HCC, poses a significant challenge. Recent mechanistic studies have shown that epithelial-mesenchymal transition or transformation (EMT), ATP binding cassette (ABC) transporters, hypoxia, autophagy, and angiogenesis are involved in apoptosis, angiogenesis, HCC cell proliferation, and TKI resistance in patients with HCC. Exploring and overcoming such resistance mechanisms is essential to extend the therapeutic benefits of TKIs to patients with TKI-resistant HCC. This review aims to summarize the potential resistance mechanism proposed in recent years and methods to reverse TKI resistance in the context of HCC.

Bisegmentectomy 7-8 for Small-for-Size Remanant Liver for Cirrhotic Patients Under Right Hemi-hepatectomy With Hepatocellular Carcinoma: A Case-Matched Comparative Study.

Aim: To compare the short- and long-term treatment outcomes of bisegmentectomy 7-8 vs. right hepatectomy for patients with hepatocellular carcinoma and cirrhosis. Methods: Thirty six cirrhotic HCC patients with infiltration of right hepatic vein in segments 7-8 underwent bisegmentectomy 7-8 for small-for-size remanant liver under right hemi-hepatectomy. Its outcome was compared with a case-matched control group of cirrhotic HCC patients who underwent right hemi-hepatectomy during the study period. Results: The study group consisted of 36 patients and the control group 36 patients selected from 1,526 patients matched with age, tumor size, tumor location, and Pugh-Child staging. There were no significant differences between the two groups in operative parameters and in perioperative main complications which included hemorrhage, bile leakage, ascites, pleural effusion, and liver failure. The overall morbidity rate and morbidity rate classified according to Clavien's classification were similar. There was no in-hospital mortality or 90 day post-operative mortality. The mean follow-up was 30 and 32 months for the study group and control group, respectively. The disease free survival rate (DFS) for the study group was just significantly better than the control group. The median DFS was 24 months for the study group and 8 months for the control group (P = 0.049). Meanwhile, the median cumulative overall survival was 35 months for the study group and 27 months for the control group (P = 0.494). Conclusion: Bisegmentectomy 7-8 was safe and feasible for selected cirrhosis patients, and did not increase the perioperative risk and inferior long-term overall survival outcomes. It extended the indications for liver resection in patients with borderline volumes of future liver remnant for HCC cirrhotic liver.

Association of Preoperative NANOG-Positive Circulating Tumor Cell Levels With Recurrence of Hepatocellular Carcinoma.

BACKGROUND: Cancer stem cells (CSCs) and Circulating tumor cells (CTCs) have been proposed as fundamental causes for the recurrence of hepatocellular carcinoma (HCC). CTCs isolated from patients with HCC illustrate a unique Nanog expression profile analysis. The aim of this study was to enhance the prediction of recurrence and prognosis of the CTC phenotype in patients with HCC by combining Nanog expression into a combined forecasting model. SUBJECTS MATERIALS AND METHODS: We collected 320 blood samples from 160 patients with HCC cancer before surgery and used CanPatrol™ CTC enrichment technology and in situ hybridization (ISH) to enrich and detect CTCs and CSCs. Nanog expression in all CTCs was also determined. In addition, RT-PCR and immunohistochemistry were used to study the expression of Nanog, E-Cadherin, and N-Cadherin in liver cancer tissues and to conduct clinical correlation studies. RESULTS: The numbers of EpCAM mRNA+ CTCs and Nanog mRNA+ CTCs were strongly correlated with postoperative HCC recurrence (CTC number (P = 0.03), the total number of mixed CTCS (P = 0.02), and Nanog> 6.7 (P = 0.001), with Nanog > 6.7 (P = 0.0003, HR = 2.33) being the most crucial marker. There are significant differences in the expression of Nanog on different types of CTC: most Epithelial CTCs do not express Nanog, while most of Mixed CTC and Mesenchymal CTC express Nanog, and their positive rates are 38.7%, 66.7%, and 88.7%, respectively, (P=0.0001). Moreover, both CTC (≤/> 13.3) and Nanog (≤/>6.7) expression were significantly correlated with BCLC stage, vascular invasion, tumor size, and Hbv-DNA (all P < 0.05). In the young group and the old group, patients with higher Nanog expression had a higher recurrence rate. (P < 0.001). CONCLUSIONS: The number of Nanog-positive cells showed positive correlation with the poor prognosis of HCC patients. The detection and analysis of CTC markers (EpCAM and CK8, 18, CD45 Vimentin,Twist and 19) and CSCs markers (NANOG) are of great value in the evaluation of tumor progression.