Cell lines

Human OS cell lines HOS and 143B

Preparation Method

Cells were cultured in high glucose Dulbecco’s modified Eagle’s medium supplemented with 10% fetal bovine serum and 1% penicillin streptomycin at 37℃.

Reaction Conditions

Different concentrations (0, 2.5, 5, 10, 20, and 40 μg/ml) of atezolizumab were applied to human OS cell lines HOS and 143B for 24 h.

Applications

Atezolizumab inhibits proliferation and induces immune independent apoptosis of osteosarcoma cells. The proliferation of HOS and 143B both were inhibited by atezolizumab in a dose-dependent manner. The IC₅₀values of HOS and 143B were between 10-20 μg/ml.

Animal models

male C57BL/6 mice (age, 8-10 weeks old; weight, 20-25 g)

Preparation Method

The sepsis model was generated using the cecal ligation and puncture (CLP) procedure. Mice were anesthetized by intraperiton- eal injection of 40 mg/kg pentobarbital sodium. an incision was made in the lower abdomen. The cecum was ligated in the middle, and the distal cecum was punctured right through using a 21-gauge needle. Squeezed a small amount of stool into the abdominal cavity, and closed the abdominal incision layer by layer.

Dosage form

100 μg on days 1 and 4

Applications

Atezolizumab treatment reduces endotoxin levels and intestinal mucosal permeability as well as decreases ileum histological scores in septic mice. However, atezolizumab treatment increases the expression of tight junction proteins in the ileum during sepsis.

• Clin Transl Med 12.6 (2022): e901. PMID:35696531

Atezolizumab, a specific monoclonal antibody against PD-L1, can inhibit the combination between PD-L1 and PD-1. Therefore, it showed various promising effects, such as inhibiting the proliferation and induce immune-independent apoptosis of osteosarcoma cells and reducing immunosuppression caused by T lymphocyte apoptosis in various cancer types.^[1][2]

In vitro study indicated that atezolizumab could cause mitochondrial damage to induce the imbalance between oxidants and antioxidants and induce mitochondria-related apoptosis in OS cells by activating JNK pathway. Furthermore, atezolizumab induced autophagy, however, inhibition of autophagy enhances atezolizumab-induced apoptosis in osteosarcoma cells.^[2]

Study demonstrated that atezolizumab could suppress the proliferation of OS cells in vivo, and the suppression was further enhanced by the combination of CQ. Besides, atezolizumab promoted apoptosis of OS cells in vivo, and this phenomenon was exacerbated by the addition of CQ. Moreover, atezolizumab could increase the content of MDA while increasing the positive rate of ROS in OS.^[2]

References:
[1]. Chen J, et al. Atezolizumab alleviates the immunosuppression induced by PD-L1-positive neutrophils and improves the survival of mice during sepsis. Mol Med Rep. 2021 Feb;23(2):144.
[2]. Liu Z, et al. Targeting autophagy enhances atezolizumab-induced mitochondria- related apoptosis in osteosarcoma. Cell Death Dis. 2021 Feb 8;12(2):164.