Dose-dependent bidirectional pharmacological effects of vinorelbine-based metronomic combination chemotherapy on tumor growth and metastasis and mechanisms in melanoma mouse model.

BACKGROUND: There is evidence that the empirical setting of doses and schedules of antineoplastic agents in metronomic chemotherapy (MC) might lead to undesirable outcomes, such as promoting tumor growth or metastasis at certain low doses. However, details about the dose effect of antineoplastic agents in MC have not been fully known yet. OBJECTIVES: Vinorelbine combined with cisplatin or fluorouracil (VNR/CDDP or VNR/FU) was selected to investigate its effects on tumor growth or metastasis as well as mechanisms. METHODS: Experimental techniques, including immunohistochemistry, western blot, immunofluorescence, and flow cytometry, were used to explore the mechanisms, along with cell proliferation, apoptosis, migration, and invasion. RESULTS: The results showed that VNR/CDDP or VNR/FU promoted tumor growth and metastasis at low doses and inhibited them at high ones. Except that expressions of apoptotic proteins were elevated at both low and high doses, low-dose treatments enhanced angiogenesis and promoted the mobilization and recruitment of myeloid-derived suppressor cells (MDSCs), while high-dose treatments reversed these effects. Additionally, low concentrations of VNR/CDDP or VNR/FU stimulated tumor cell functions such as anti-apoptosis, migration, and invasion, but high concentrations only suppressed cell proliferation and increased apoptosis. CONCLUSION: This study elucidated a bidirectional action mode regulated by multiple mechanisms at different doses in MC and also highlighted the risks of low-dose metronomic administration of antineoplastic agents in the clinic. More preclinical and clinical studies focusing on the dose-effect of metronomic regimens are urgently needed because an effective therapeutic regimen should be an optimal setting of drugs, doses, schedules, or combinations.

Low-dose Cisplatin Induces Tumor Growth via Mobilization of Proangiogenic Bone Marrow-derived Cells in Mouse Models.

BACKGROUND/AIM: It is generally accepted that low-dose metronomic (LDM) chemotherapy mostly exerts its antitumor effects by inhibiting tumor angiogenesis. However, there is some evidence that LDM chemotherapy subsequently promotes tumor angiogenesis under certain regimens in animal models. The mechanisms responsible for these contradictory results are unclear. MATERIALS AND METHODS: Cisplatin (CDDP) was intraperitoneally administered to tumor-bearing mice at doses of 0.05-3 mg/kg every other day. The effects of LDM chemotherapy with CDDP on tumor growth and angiogenesis were observed. To determine the involved mechanisms, we analyzed the expression of vascular basement membrane proteins, transcription of angiogenesis-related genes in tumor tissues, and mobilization of proangiogenic bone marrow-derived cells (BMDCs) in circulating blood. RESULTS: The mean tumor weight with the 3 mg/kg q.o.d. regimen CDDP was significantly lower (by 57.3%) in the CDDP than in the control group. However, the tumor weight was 52.1% higher for the 0.19 mg/kg q.o.d. regimen in the CDDP group, which could be antagonized using 30 mg/kg all-trans retinoic acid. For the 0.19 mg/kg q.o.d., more tumor vascular structures were observed in the CDDP than in the control group (47.9±5.0 vs. 22.3±0.8, p<0.001). The mobilization of VEGFR2+ BMDCs and the mRNA expression of the proangiogenic genes MMP9, VEGFR1, VEGFR2 and VE-cadherin were increased in the 0.19 mg/kg regimen. CONCLUSION: These results indicate that metronomic CDDP promoted tumor angiogenesis and tumor growth via increased mobilization of proangiogenic BMDCs at certain low doses. This implies a potential therapeutic risk from an inappropriate LDM chemotherapy dosage and suggests that optimizing the LDM chemotherapy regimen is urgently needed.

Quantitative evaluation and pharmacokinetic characteristics of the irreversible BTK inhibitor zanubrutinib in mouse plasma using LC-MS/MS.

Zanubrutinib (BGB-3111) belongs to the class of irreversible inhibitors of Bruton's tyrosine kinase (BTK) for treating B-cell malignancies. A validated assay with excellent sensitivity, selectivity, and simplicity is required to measure plasma concentration and investigate its pharmacokinetics. The plasma of mice containing zanubrutinib and roxithromycin (internal standard) was processed with acetonitrile for protein precipitation. Then the supernatant was analyzed by high-performance liquid chromatography coupled with a triple quadrupole mass spectrometer using electrospray ionization in the positive mode. Zanubrutinib was given to mice intragastrically at 30 mg/kg to determine its pharmacokinetic parameters. The method was verified and showed good linearity in the range of 0.1-100 ng/mL. The method's sensitivity, accuracy, and precision were all within acceptable bounds. By this method, the pharmacokinetic profile of zanubrutinib in mouse plasma was measured.

Alpha-solanine Anti-tumor Effects in Non-small Cell Lung Cancer Through Regulating the Energy Metabolism Pathway.

BACKGROUND: Lung cancer is a malignant tumor with a high incidence in China, especially non-small cell lung cancer (NSCLC), which is the main threat to human life, with terrible morbidity and mortality. The research on the treatment and mechanism of NSCLC has been the forefront and hotspot of research. Recent patents show that alpha-solanine (α-solanine) exhibits the best anti-cancer activity, although its target and related mechanism remain to be elucidated. OBJECTIVES: This study aims to explore the possible targets and mechanisms of α-solanine in the treatment of NSCLC through network pharmacology and experimental verification. METHODS: Network pharmacology was applied to screen the possible targets of α-solanine on NSCLC, construct core networks, and perform GO enrichment and KEGG pathway analysis to predict the mechanism of α-solanine against NSCLC. Experiments were implemented to verify the results of network pharmacology in vitro. The A549 and PC-9 cells were exposed to α-solanine to assess the anti-tumor effect. Cell apoptosis was determined by the Annexin-V/PI assay. Targeted energy metabolomics was used to validate the network pharmacology results, and energy metabolism pathway- related proteins were detected by immunofluorescence and western blot. RESULTS: Network pharmacology showed that there were 130 potential targets of α-solanine and NSCLC. GO, and KEGG analysis showed that the energy metabolism pathway is the main pathway for α-solanine to exert anti-tumor effects on NSCLC. Experimental results showed that α-solanine inhibited cell proliferation, migration, invasion and promoted cell apoptosis. At the same time, after α-solanine treatment, the energy metabolism pathway-related proteins, including GPI, ALDOA, TPI1, PKLR, LDHA, and ALDH3, were expressed reduced. In addition, α-solanine also affects the amino acid metabolism of A549 and PC-9 cells. CONCLUSION: Based on a combination of network pharmacological prediction and experimental verification, α-solanine may exert anti-NSCLC effects by regulating the energy metabolism pathway.