Chloroquine suppresses proliferation and invasion and induces apoptosis of osteosarcoma cells associated with inhibition of phosphorylation of STAT3

Metformin and chloroquine enhanced the efficacy of cytarabine in acute lymphoblastic leukemia cell lines: a drug repositioning approach

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Despite advances in the treatment of ALL, high disease recurrence and the impact of chemical toxicity on patients' quality of life persist. Drug repositioning has been proven to have antitumor and anti-inflammatory properties in leukemia. This study investigated the effects of metformin and chloroquine on the efficacy of cytarabine in NALM-6 cells. The growth inhibitory effects of metformin (Met) and chloroquine (CQ) on the response of NALM-6 cells to cytarabine (AraC) were determined via the MTT assay. To test the regeneration potential, a colony formation assay was performed. Apoptosis and cell cycle analyses were executed via flow cytometry. Oxidative stress markers and antioxidant activity were measured. Gene expression analysis and protein measurement of apoptotic and signaling pathways were performed. The administration of metformin and chloroquine increased the efficacy of cytarabine in suppressing NALM-6 cells, leading to decreased colony formation, increased apoptosis, and G1 phase cell cycle arrest. These effects are mediated by the upregulation of TP53, CASP3 and CASP8 genes and the reduction in BCL-2, NRAS and KRAS genes. Our data suggest that the combination of AraC with Met and CQ may be an effective approach for the treatment of B-ALL.

Studies on Autophagy and Apoptosis of Fibrosarcoma HT-1080 Cells Mediated by Chalcone with Indole Moiety

This study demonstrated the anticancer efficacy of chalcones with indole moiety (MIPP, MOMIPP) in fibrosarcoma cells for the first time. The results showed that MIPP and MOMIPP reduced the viability of HT-1080 cells in a concentration-dependent manner. MOMIPP was more active than MIPP in HT-1080 cells, showing lower IC50 values (3.67 vs. 29.90 μM). Both compounds at a concentration of 1 μM induced apoptosis in HT-1080 cells, causing death strictly related to caspase activation, as cell viability was restored when the caspase inhibitor Z-VAD was added. Reactive oxygen species production was approximately 3-fold higher than in control cells, and cotreatment with the inhibitor of mitochondrial ATPase oligomycin diminished this effect. Such effects were also reflected in mitochondrial dysfunction, including decreased membrane potential. Interestingly, the compounds that were studied caused massive vacuolization in HT-1080 cells. Immunocytochemical staining and TEM analysis showed that HT-1080 cells exhibited increased expression of the LC3-II protein and the presence of autophagosomes with a double membrane, respectively. Both compounds induced apoptosis, highlighting a promising link between autophagy and apoptosis. This connection could be a new target for therapeutic strategies to overcome chemoresistance, which is a significant cause of treatment failure and tumour recurrence in fibrosarcoma following traditional chemotherapy.

Repurposing synthetic and natural derivatives induces apoptosis in an orthotopic glioma-induced xenograft model by modulating WNT/β-catenin signaling

BACKGROUND

Glioblastomas arise from multistep tumorigenesis of the glial cells. Despite the current state-of-art treatment, tumor recurrence is inevitable. Among the innovations blooming up against glioblastoma, drug repurposing could provide profound premises for treatment enhancement. While considering this strategy, the efficacy of the repurposed drugs as monotherapies were not up to par; hence, the focus has now shifted to investigate the multidrug combinations.

AIM

To investigate the efficacy of a quadruple-combinatorial treatment comprising temozolomide along with chloroquine, naringenin, and phloroglucinol in an orthotopic glioma-induced xenograft model.

METHODS

Antiproliferative effect of the drugs was assessed by immunostaining. The expression profiles of WNT/β-catenin and apoptotic markers were evaluated by qRT-PCR, immunoblotting, and ELISA. Patterns of mitochondrial depolarization was determined by flow cytometry. TUNEL assay was performed to affirm apoptosis induction. In vivo drug detection study was carried out by ESI-Q-TOF MS analysis.

RESULTS

The quadruple-drug treatment had significantly hampered glioma proliferation and had induced apoptosis by modulating the WNT/β-catenin signaling. Interestingly, the induction of apoptosis was associated with mitochondrial depolarization. The quadruple-drug cocktail had breached the blood-brain barrier and was detected in the brain tissue and plasma samples.

CONCLUSION

The quadruple-drug combination served as a promising adjuvant therapy to combat glioblastoma lethality in vivo and can be probed for translation from bench to bedside.

Tocilizumab (monoclonal anti-IL-6R antibody) reverses anlotinib resistance in osteosarcoma

Purpose

Anlotinib, a tyrosine kinase inhibitor (TKI) has been in clinical application to inhibit malignant cell growth and lung metastasis in osteosarcoma (OS). However, a variety of drug resistance phenomena have been observed in the treatment. We aim to explore the new target to reverse anlotinib resistance in OS.

Materials and Methods

In this study, we established four OS anlotinib-resistant cell lines, and RNA-sequence was performed to evaluate differentially expressed genes. We verified the results of RNA-sequence by PCR, western blot and ELISA assay. We further explored the effects of tocilizumab (anti- IL-6 receptor), either alone or in combined with anlotinib, on the inhibition of anlotinib-resistant OS cells malignant viability by CCK8, EDU, colony formation, apoptosis, transwell, wound healing, Cytoskeletal stain assays, and xenograft nude mouse model. The expression of IL-6 in 104 osteosarcoma samples was tested by IHC.

Results

We found IL-6 and its downstream pathway STAT3 were activated in anlotinib-resistant osteosarcoma. Tocilizumab impaired the tumor progression of anlotinib-resistant OS cells, and combined treatment with anlotinib augmented these effects by inhibiting STAT3 expressions. IL-6 was highly expressed in patients with OS and correlated with poor prognosis.

Conclusion

Tocilizumab could reverse anlotinib resistance in OS by IL-6/STAT3 pathway and the combination treatment with anlotinib rationalized further studies and clinical treatment of OS.

Nanosized drug delivery strategies in osteosarcoma chemotherapy

Despite recent developments worldwide in the therapeutic care of osteosarcoma (OS), the ongoing challenges in overcoming limitations and side effects of chemotherapy drugs warrant new strategies to improve overall patient survival. Spurred by rapid progress in biomedicine, nanobiotechnology, and materials chemistry, chemotherapeutic drug delivery in treatment of OS has become possible in recent years. Here, we review recent advances in the design of drug delivery system, especially for chemotherapeutic drugs in OS, and discuss the relative merits in trials along with future therapeutic options. These advances may pave the way for novel therapies requisite for patients with OS.

Effects of STAT3 on aging-dependent neovascularization impairment following limb ischemia: from bedside to bench

Aging is a major risk factor for ischemic hypoxia-related diseases, including peripheral artery diseases (PADs). Signal transducer and activator of transcription 3 (STAT3) is a critical transcription activator in angiogenesis. Nevertheless, the effect of aging on endothelial cells and their responses to hypoxia are not well studied. Using a hindlimb hypoxic/ischemic model of aged mice, we found that aged mice (80-100-week-old) expressed significantly lower levels of angiogenesis than young mice (10-week-old). In our in vitro study, aged endothelial cells (≥30 passage) showed a significant accumulation of β-galactosidase and a high expression of aging-associated genes, including p16, p21, and hTERT compared with young cells (<10 passage). After 24 hours of hypoxia exposure, proliferation, migration and tube formation were significantly impaired in aged cells compared with young cells. Notably, STAT3 and angiogenesis-associated proteins such as PI3K/AKT were significantly downregulated in aged mouse limb tissues and aged cells. Further, using STAT3 siRNA, we found that suppressing STAT3 expression in endothelial cells impaired proliferation, migration and tube formation under hypoxia. Correspondingly, in patients with limb ischemia we also observed a higher expression of circulating STAT3, associated with a lower rate of major adverse limb events (MALEs). Collectively, STAT3 could be a biomarker reflecting the development of MALE in patients and also a regulator of age-dependent angiogenesis post limb ischemia. Additional studies are required to elucidate the clinical applications of STAT3.