The expression of copper transporters associated with the ototoxicity induced by platinum-based chemotherapeutic agents

5-FU promotes HBV replication through oxidative stress-induced autophagy dysfunction

BACKGROUND & AIMS

Hepatitis B virus (HBV) reactivation is a major problem that must be overcome during chemotherapy for HBV-related hepatocellular carcinoma (HCC). However, the mechanism underlying chemotherapy-associated HBV reactivation is still not fully understood, hindering the development of improved HBV-related HCC treatments.

METHODS

A meta-analysis was performed to assess the HBV reactivation risk during transcatheter arterial chemoembolization (TACE). To investigate the regulatory effects and mechanisms of 5-FU on HBV replication, an HBV mouse model was established by pAAV-HBV1.2 hydrodynamic injection followed by intraperitoneal 5-FU injection, and different in vitro models (HepG2.2.15 or Huh7 cells) were established. Realtime RT‒qPCR, western blotting, luciferase assays, and immunofluorescence were used to determine viral parameters. We also explored the underlying mechanisms by RNA-seq, oxidative stress evaluation and autophagy assessment.

RESULTS

The pooled estimated rate of HBV reactivation in patients receiving TACE was 30.3 % (95 % CI, 23.1%-37.4 %). 5-FU, which is a chemotherapeutic agent commonly used in TACE, promoted HBV replication in vitro and in vivo. Mechanistically, 5-FU treatment obviously increased autophagosome formation, as shown by increased LC3-II levels. Additionally, 5-FU impaired autophagic degradation, as shown by marked p62 and mCherry-GFP-LC3 upregulation, ultimately promoting HBV replication and secretion. Autophagy inhibition by 3-methyladenine or chloroquine significantly altered 5-FU-induced HBV replication. Furthermore, 5-FU-induced autophagy and HBV replication were markedly attenuated with a reactive oxygen species (ROS) scavenger.

CONCLUSIONS

Together, our results indicate that ROS-induced autophagosome formation and autophagic degradation play a critical role in 5-FU-induced HBV reactivation.

Biopolymer Lipid Hybrid Microcarrier for Transmembrane Inner Ear Delivery of Dexamethasone

Dexamethasone is one of the most often used corticosteroid drugs for sensorineural hearing loss treatment, and is used either by intratympanic injection or through systemic delivery. In this study, a biopolymer lipid hybrid microcarrier was investigated for enhanced local drug delivery and sustained release at the round window membrane level of the middle ear for the treatment of sensorineural hearing loss (SNHL). Dexamethasone-loaded and dexamethasone-free microparticles were prepared using biopolymers (polysaccharide and protein, pectin and bovine serum albumin, respectively) combined with lipid components (phosphatidylcholine and Dimethyldioctadecylammonium bromide) in order to obtain a biopolymer–liposome hybrid system, with a complex structure combining to enhance performance in terms of physical and chemical stability. The structure of the microparticles was evaluated by FTIR, XRD, thermal analysis, optical microscopy, and scanning electron microscopy (SEM). The encapsulation efficiency determination and the in vitro Dexamethasone release study were performed using UV-Vis spectroscopy. The high value of encapsulation efficiency and the results of the release study indicated six days of sustained release, encouraging us to evaluate the in vitro cytotoxicity of Dexamethasone-loaded microparticles and their influence on the cytotoxicity induced by Cisplatin on auditory HEI-OC1 cells. The results show that the new particles are able to protect the inner ear sensory cells.

The Effects of Chemotherapeutics on the Ovarian Cancer Microenvironment

High-grade serous ovarian cancer (HGSOC) is characterized by a complex and dynamic tumor microenvironment (TME) composed of cancer-associated fibroblasts (CAFs), immune cells, endothelial cells, and adipocytes. Although most approved therapies target cancer cells, a growing body of evidence suggests that chemotherapeutic agents have an important role in regulating the biology of the diverse cells that compose the TME. Understanding how non-transformed cells respond and adapt to established therapeutics is necessary to completely comprehend their action and develop novel therapeutics that interrupt undesired tumor-stroma interactions. Here, we review the effects of chemotherapeutic agents on normal cellular components of the host-derived TME focusing on CAFs. We concentrate on therapies used in the treatment of HGSOC and synthesize findings from studies focusing on other cancer types and benign tissues. Agents such as platinum derivatives, taxanes, and PARP inhibitors broadly affect the TME and promote or inhibit the pro-tumorigenic roles of CAFs by modifying the bidirectional cross-talk between tumor and stromal cells in the tumor organ. While most chemotherapy research focuses on cancer cells, these studies emphasize the need to consider all cell types within the tumor organ when evaluating chemotherapeutics.

Natural products as a means of overcoming cisplatin chemoresistance in bladder cancer

Cisplatin remains an integral part of the treatment for muscle invasive bladder cancer. A large number of patients do not respond to cisplatin-based chemotherapy and efficacious salvage regimens are limited. Immunotherapy has offered a second line of treatment; however, only approximately 20% of patients respond, and molecular subtyping of tumors indicates there may be significant overlap in those patients that respond to cisplatin and those patients that respond to immunotherapy. As such, restoring sensitivity to cisplatin remains a major hurdle to improving patient care. One potential source of compounds for enhancing cisplatin is naturally derived bioactive products such as phytochemicals, flavonoids and others. These compounds can activate a diverse array of different pathways, many of which can directly promote or inhibit cisplatin sensitivity. The purpose of this review is to understand current drug development in the area of natural products and to assess how these compounds may enhance cisplatin treatment in bladder cancer patients.

New insights in gene expression alteration as effect of doxorubicin drug resistance in triple negative breast cancer cells

Background

Triple negative breast cancer (TNBC) is a heterogeneous disease with aggressive behavior and an unfavorable prognosis rate. Due to the lack of surface receptors, TNBC must be intensely investigated in order to establish a suitable treatment for patients with this pathology. Chemoresistance is an important reason for therapeutic failure in TNBC.

Method

The aim of this study was to investigate the effect of doxorubicin in TNBC cell lines and to highlight cellular and molecular alterations after a long exposure to doxorubicin.

Results

The results revealed that doxorubicin significantly increased the half maximal inhibitory concentration (IC₅₀) values at P12 and P24 compared to parenteral cells P0. Modifications in gene expression were investigated through microarray technique, and for detection of mutational pattern was used Next Generation Sequencing (NGS). 196 upregulated and 115 downregulated genes were observed as effect of multiple dose exposure, and 15 overexpressed genes were found to be involved in drug resistance. Also, the presence of some additional mutations in both cell lines was observed.

Conclusion

The outcomes of this research may provide novel biomarkers for drug resistance in TNBC. Also, this activity can highlight the potential mechanisms associated with drug resistance, as well as the potential therapies to counteract these mechanisms.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s13046-020-01736-2.