A novel role for apatinib in enhancing radiosensitivity in non-small cell lung cancer cells by suppressing the AKT and ERK pathways

Recent advances progress of targeted drugs combined with radiotherapy for advanced non-small cell lung cancer: a review

Targeted drug therapy plays an important role in the clinical application of non-small cell lung cancer, especially adenocarcinoma. However, for patients with advanced disease, drug resistance after targeted therapy, unclear target, and other reasons that cannot or do not want surgery, the combination of chemotherapy, radiotherapy, immunity, etc. is often used. The synergistic effect of targeted drugs and radiotherapy in non-small cell lung cancer has shown good clinical efficacy. This article reviews the clinical progress of targeted drug therapy combined with radiotherapy in advanced non-small cell lung cancer in recent years, in order to provide new ideas for further clinical research of this treatment mode.

Low- dose Apatinib promotes vascular normalization and hypoxia reduction and sensitizes radiotherapy in lung cancer

BACKGROUND AND PURPOSE

Abnormal vascular network of tumor can create a hypoxic microenvironment, and reduce radiotherapy sensitivity. Normalization of tumor vasculature can be a new therapeutic strategy for sensitizing radiotherapy. This study aimed to explore the effect of apatinib on vascular normalization, as well as the syngeneic effect with radiotherapy on lung cancer.

MATERIALS AND METHODS

Lewis lung carcinoma (LLC) xenograft-bearing female C57BL/6 mice were treated with different doses of apatinib (30, 60, and 120 mg/kg per day) and/or radiation therapy (8 Gy/1F) and then sacrificed to harvest tumor tissue for immunohistochemical test. Further ¹⁸ F-FMISO micro- PET in vivo explored the degree of hypoxia.

RESULTS

Immunohistochemistry of CD31 and alpha-smooth muscle actin (α-SMA) proved that low-dose apatinib can normalize vasculature in tumor, especially on Day 10. Tissue staining of hypoxyprobe-1 and ¹⁸ F-FMISO micro- PET in vivo showed that 60 mg/kg/day of apatinib significantly alleviates hypoxia. Moreover, this study further proved that low-dose apatinib (60 mg/kg/day) can enhance the radio-response of LLC xenograft mice.

CONCLUSION

Our data suggested that low- dose apatinib can successfully induce a vascular normalization window and function as a radio- sensitizer in the lung cancer xenografts model.

Current Landscape of Therapeutic Resistance in Lung Cancer and Promising Strategies to Overcome Resistance

Lung cancer is one of the leading causes of cancer-related deaths worldwide with a 5-year survival rate of less than 18%. Current treatment modalities include surgery, chemotherapy, radiation therapy, targeted therapy, and immunotherapy. Despite advances in therapeutic options, resistance to therapy remains a major obstacle to the effectiveness of long-term treatment, eventually leading to therapeutic insensitivity, poor progression-free survival, and disease relapse. Resistance mechanisms stem from genetic mutations and/or epigenetic changes, unregulated drug efflux, tumor hypoxia, alterations in the tumor microenvironment, and several other cellular and molecular alterations. A better understanding of these mechanisms is crucial for targeting factors involved in therapeutic resistance, establishing novel antitumor targets, and developing therapeutic strategies to resensitize cancer cells towards treatment. In this review, we summarize diverse mechanisms driving resistance to chemotherapy, radiotherapy, targeted therapy, and immunotherapy, and promising strategies to help overcome this therapeutic resistance.