The Molecular Mechanism of Human Voltage-Dependent Anion Channel 1 Blockade by the Metallofullerenol Gd@C82(OH)22: An In Silico Study

The endohedral metallofullerenol Gd@C82(OH)22 has been identified as a possible antineoplastic agent that can inhibit both the growth and metastasis of cancer cells. Despite these potentially important effects, our understanding of the interactions between Gd@C82(OH)22 and biomacromolecules remains incomplete. Here, we study the interaction between Gd@C82(OH)22 and the human voltage-dependent anion channel 1 (hVDAC1), the most abundant porin embedded in the mitochondrial outer membrane (MOM), and a potential druggable target for novel anticancer therapeutics. Using in silico approaches, we observe that Gd@C82(OH)22 molecules can permeate and form stable interactions with the pore of hVDAC1. Further, this penetration can occur from either side of the MOM to elicit blockage of the pore. The binding between Gd@C82(OH)22 and hVDAC1 is largely driven by long-range electrostatic interactions. Analysis of the binding free energies indicates that it is thermodynamically more favorable for Gd@C82(OH)22 to bind to the hVDAC1 pore when it enters the channel from inside the membrane rather than from the cytoplasmic side of the protein. Multiple factors contribute to the preferential penetration, including the surface electrostatic landscape of hVDAC1 and the unique physicochemical properties of Gd@C82(OH)22. Our findings provide insights into the potential molecular interactions of macromolecular biological systems with the Gd@C82(OH)22 nanodrug.

Repositioning of Etravirine as a Potential CK1ε Inhibitor by Virtual Screening

CK1ε is a key regulator of WNT/β-catenin and other pathways that are linked to tumor progression; thus, CK1ε is considered a target for the development of antineoplastic therapies. In this study, we performed a virtual screening to search for potential CK1ε inhibitors. First, we characterized the dynamic noncovalent interactions profiles for a set of reported CK1ε inhibitors to generate a pharmacophore model, which was used to identify new potential inhibitors among FDA-approved drugs. We found that etravirine and abacavir, two drugs that are approved for HIV infections, can be repurposed as CK1ε inhibitors. The interaction of these drugs with CK1ε was further examined by molecular docking and molecular dynamics. Etravirine and abacavir formed stable complexes with the target, emulating the binding behavior of known inhibitors. However, only etravirine showed high theoretical binding affinity to CK1ε. Our findings provide a new pharmacophore for targeting CK1ε and implicate etravirine as a CK1ε inhibitor and antineoplastic agent.

Ginsenoside CK Inhibits TGF-β-Induced Epithelial-Mesenchymal Transition in A549 Cell via SIRT1

Ginsenoside CK is the main metabolite of protopanaxadiol saponins in intestinal bacteria. Previous studies have shown that ginsenoside CK can affect many aspects of tumor development through a variety of mechanisms. However, few studies have reported the antimetastatic effects of ginsenoside CK in non-small-cell lung cancer (NSCLC). In this study, we explored the effect of ginsenoside CK on epithelial-mesenchymal transition (EMT) induced by TGF-β in A549 cells and the potential molecular mechanisms. Our data showed that ginsenoside CK effectively prevented TGF-β-induced EMT, as indicated by the upregulation of E-cadherin and downregulation of vimentin. Furthermore, ginsenoside CK inhibited the metastatic ability of A549 cells in the tail vein lung metastasis model of nude mice. Additionally, ginsenoside CK decreased the expression of silent information regulator 2 homolog 1 (SIRT1) in the inhibition of EMT induced by TGF-β. Moreover, the antimetastatic effect of ginsenoside CK was reversed by SIRT1 overexpression. Generally, our results indicated the antimetastatic effect and underlying mechanism of ginsenoside CK on TGF-β-induced EMT in A549 cells, suggesting that ginsenoside CK can be used as an effective antineoplastic agent.

Weight Gain and Loss In Cancer Patients Undergoing Chemotherapy: Importance of Dose Adjustment

Introduction: The established dose of chemotherapy is based on the values of the patient's body weight, where variations during treatment can increase the toxicity of chemotherapy, with the development of nephrotoxicity, among other toxicity profiles, as well as in cases of weight gain, patients may receive low doses and compromise the therapeutic response to the tumor. Objective: to evaluate weight gain and loss in cancer patients undergoing chemotherapy. Methods: Longitudinal analytical study with patients at the end of chemotherapy treatment of both genders. The type, location of the tumor and the antineoplastic agent used were collected from the medical records, as well as height and weight at the beginning of treatment. At the time of collection, anthropometric assessment was performed using body mass index, arm circumference, arm muscle circumference, triceps skinfold thickness and percentage of weight loss. Results: Among the patients included in the study, 47.5% had a weight gain of around 2.5 kg, while the remaining patients (52.5%) had a weight loss of around 2.8 kg. Of the patients who had GFR, 55.5% had severe PP, 33.4% had no significant loss and 11.1 had significant loss. In the current study, only 22% had a GFR <60ml/min/1.73m², but they would already need to readjust the medication calculation. Conclusion: It is important to evaluate body surface variations and also the GFR to adjust the dose of the antineoplastic agent and to prevent or minimize nephrotoxicity, as well as to reduce the risk of underdosing and inefficiency of the therapy.

Sensitizing tumors to anti-PD-1 therapy by promoting NK and CD8+ T cells via pharmacological activation of FOXO3

BackgroundStimulating antitumor immunity by blocking programmed death-1 (PD-1) or its ligand (programmed death-ligand 1 (PD-L1) is a promising antitumor therapy. However, numerous patients respond poorly to PD-1/PD-L1 blockade. Unresponsiveness to immune-checkpoint blockade (ICB) can cast significant challenges to the therapeutic options for patients with hard-to-treat tumors. There is an unmet clinical need to establish new therapeutic approaches for mitigating ICB unresponsiveness in patients. In this study, we investigated the efficacy and role of low-dose antineoplastic agent SN-38 or metformin in sensitizing unresponsive tumors to respond to ICB therapy.MethodsWe assessed the significant pathological relationships between PD-L1 and FOXO3 expression and between PD-L1 and c-Myc or STAT3 expression in patients with various tumors. We determined the efficacy of low-dose SN-38 or metformin in sensitizing unresponsive tumors to respond to anti-PD-1 therapy in a syngeneic tumor system. We deciphered novel therapeutic mechanisms underlying the SN-38 and anti-PD-1 therapy-mediated engagement of natural killer (NK) or CD8+ T cells to infiltrate tumors and boost antitumor immunity.ResultsWe showed that PD-L1 protein level was inversely associated with FOXO3 protein level in patients with ovarian, breast, and hepatocellular tumors. Low-dose SN-38 or metformin abrogated PD-L1 protein expression, promoted FOXO3 protein level, and significantly increased the animal survival rate in syngeneic mouse tumor models. SN-38 or metformin sensitized unresponsive tumors responding to anti-PD-1 therapy by engaging NK or CD8+ T cells to infiltrate the tumor microenvironment (TME) and secret interferon-γ and granzyme B to kill tumors. SN-38 suppressed the levels of c-Myc and STAT3 proteins, which controlled PD-L1 expression. FOXO3 was essential for SN38-mediated PD-L1 suppression. The expression of PD-L1 was compellingly linked to that of c-Myc or STAT3 in patients with the indicated tumors.ConclusionWe show that SN-38 or metformin can boost antitumor immunity in the TME by inhibiting c-Myc and STAT3 through FOXO3 activation. These results may provide novel insight into ameliorating patient response to overarching immunotherapy for tumors.

Protein Binding of a Novel Platinum-Based Anticancer Agent BP-C1 Containing a Lignin-Derived Polymeric Ligand

Platinum (Pt) antineoplastic agents remain indispensable for the treatment of oncological disease. Pt-based drugs are mainly used in the therapy of ovarian cancer and non-small-cell lung carcinoma. A novel platinum-containing antineoplastic agent BP-C1 is a complex of diamminoplatinum with an oxygen-donor polymeric ligand of benzene-polycarboxylic acids, isolated from natural lignin. The aim of the study was to investigate ex vivo protein binding of BP-C1. Protein binding of BP-C1 was tested using equilibrium dialysis. Pooled blood plasma was used in the study. Control solutions contained the same dosages of BP-C1 in PBS (pH 7.2). Plasma and control solutions were submitted to equilibrium dialysis across a vertical 8 kDa cut-off membrane for 4 h at 37 °C under gentle shaking. Platinum was quantified in dialysis and retained fractions using inductively coupled plasma mass spectrometry after microwave digestion. The dialysis system was tested and validated; this showed no protein saturation with platinum. A medium degree of binding of platinum to macromolecular species of ca. 60% was observed. The study showed the maintenance of a high fraction of free BP-C1 in the bloodstream, facilitating its pharmacological activity.

Predictors of Venous Thromboembolism in Patients with Acute Myeloid Leukemia or Acute Lymphoblastic Leukemia

Introduction: The association of malignancy, largely solid tumors, with venous thromboembolism (VTE) is well-known and a widely validated score, Khorana score, guides prophylactic anticoagulation in high-risk patients. However, increasing albeit scarce evidence suggests a high incidence of VTE in patients with hematologic malignancies, which are comparable to high-risk solid tumors. In this study, we sought to explore the incidence and predictors of VTE (including the variables in the Khorana score) in patients with acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) from a large database. Methods: We performed a retrospective cohort study of patients diagnosed with AML or ALL using an aggregated de-identified data from electronic medical record of &gt;300 major hospitals in US (IBM Watson Explorys). Patients aged 20 to 79 years, diagnosed with AML or ALL within the past 5 years were included. The primary endpoint was the incidence of cancer associated VTE defined as deep vein thrombosis, pulmonary embolism or superficial vein thrombosis within 1 year of AML/ ALL diagnosis. Baseline characteristics including age, sex, race, body mass index (BMI), prothrombotic mutations (Factor V Leiden, prothrombin gene 20210A mutation), smoking status, prior history of VTE, presence of central venous catheter (CVC), antineoplastic agent use, erythropoietin (EPO) and pegylated asparaginase (PegA) use as well as baseline laboratory values (as included in Khorana score) were compared between acute leukemia patients with cancer associated VTE within 1 year to those without. Fibrinogen and D-dimer were not available to be explored. A univariate analysis was performed using two-sided chi-square test to study these baseline variables. A p-value &lt;0.05 was considered statistically significant. All statistical analyses were performed using GraphPad Prism version 9.0 (GraphPad Software, San Diego, CA, USA). Results: A total of 19,050 adult patients with a diagnosis of AML or ALL in the last 5 years were included. Of these, 1,550 patients had VTE within 1 year of acute leukemia diagnosis, with an overall incidence of 8.14%. Baseline characteristics of patients with acute leukemia with and without cancer associated VTE within 1 year were compared (Table 1). On univariate analysis, age&gt;60, Caucasian or African American race, obesity, remote or current smoking status, Factor V Leiden, prior history of VTE, presence of CVC, anemia, leukocytosis, antineoplastic agent/EPO or PegA use were all associated with an increased risk of cancer associated VTE. Interestingly, both low platelet counts (&lt;50 x 10 9/L) and high platelet counts (&gt;350 x 10 9/L) were associated with increased cancer associated VTE. Among these, prior history of VTE had the strongest association (OR 7.46). Younger age (20-39) and Asian race were in fact inversely associated with VTE. A multivariable analysis is currently underway to assess the significance of these risk factors independently towards cancer associated VTE in this AML/ALL population. Conclusions: Our study highlights and reiterates a high risk of VTE within one year of diagnosis of AML/ALL in what we believe is the largest cohort studied to date. Older age, Caucasian or African American race, smoking, prior VTE, presence of CVC, Factor V Leiden, antineoplastic agent or PegA use were associated with increased risk. Among the Khorana score variables, obesity, anemia, EPO use and leukocytosis stood out as potential risk factors for VTE in this population. Risk of VTE was however increased regardless of platelet counts, which emphasizes the need to consider surveillance or thromboprophylaxis strategies in AML/ALL patients with thrombocytopenia with presumed high bleeding risk. Lastly, young age and Asian ethnicity seem to confer some protection against thrombosis in this population. Our ongoing efforts include a multivariable analysis and examining the effect of the Khorana score risk stratification in our large cohort of AML/ALL patients. Finally, further studies will be fundamental to meet the unmet need for a specific risk stratification system(s) for patients with AML/ALL. Figure 1 Figure 1. Disclosures Nayak: BioChip Labs: Current Employment.

Hydroxyurea Induces Bone Marrow Mesenchymal Stromal Cells Senescence and Modifies Cell Functionality In Vitro

Hydroxyurea (HU) is an antineoplastic agent that functions as an antimetabolite compound by inhibiting the ribonucleotide reductase. HU acts mainly as a cytostatic drug that through DNA replication stress may trigger a premature senescence-like cell phenotype, though its influence on bone marrow-derived mesenchymal stem/stromal cell (BMMSC) functions has not elucidated yet. Our results indicate that HU inhibits the growth of human BMMSC alongside senescence-like changes in both morphology and replicative potential, provokes cell cycle arrest at the S phase without affecting cellular viability and induces the expression of senescence-associated β-galactosidase and p16INK4. Moreover, HU-induced senescent BMMSC, although they did not change MSC markers expression, exhibited reduced capacity osteogenic and adipogenic differentiation. Conversely, HU treatment increased immunoregulatory functions of BMMSC compared with untreated cells and determined by T-cell proliferation. Interestingly, HU did not influence the capacity of BMMSC to induce monocytic myeloid-derived suppressor cells. Thus, these results suggest that HU improves the BMMSC functions on the T-cell inhibition and preserves their interaction with myeloid cell compartment. Mechanistically, BMMSC under HU treatment displayed a downregulation of mTOR and p38 MAPK signaling that may explain the reduced cell differentiation and increased immunomodulation activities. Together, the results obtained in this investigation suggest that HU by inducing senescence-like phenotype of BMMSC influences their cellular differentiation and immunoregulatory functions.