CXCR4 overexpression correlates with poor prognosis in myasthenia gravis–associated thymoma

Clinical Application of 68 Ga-Pentixafor PET/CT for the Detection of Thymoma: A Pilot Study

PURPOSE

This study was designed to evaluate 68 Ga-pentixafor, which targets C-X-C chemokine receptor 4 (CXCR4), in the noninvasive diagnosis of thymomas.

PATIENTS AND METHODS

With institutional review board approval and signed informed consent, 32 patients with thymic masses were enrolled in this study, and all patients underwent 68 Ga-pentixafor PET/CT scans.

RESULTS

Among the 28 patients included in the analysis, 13 patients were diagnosed with thymomas, 9 patients with cysts, and 6 patients with other anterior mediastinal masses. 68 Ga-pentixafor identified all patients with thymomas (13/13, 100%), and the mean SUV max in all 13 thymomas lesions was 13.96±8.20, which was significantly higher than that in patients with cysts (1.54±0.88) and other anterior mediastinal masses (2.59±1.68), respectively ( P <0.001).

CONCLUSIONS

The preliminary study indicates the diagnostic utility of 68 Ga-pentixafor in thymomas and the differential diagnostic ability of 68 Ga-pentixafor in thymomas, thymic cysts and other benign anterior mediastinal masses.

The Role of the CXCL12/CXCR4/CXCR7 Chemokine Axis in Cancer

Chemokines are a family of small, secreted cytokines which regulate a variety of cell functions. The C-X-C motif chemokine ligand 12 (CXCL12) binds to C-X-C chemokine receptor type 4 (CXCR4) and C-X-C chemokine receptor type 7 (CXCR7). The interaction of CXCL12 and its receptors subsequently induces downstream signaling pathways with broad effects on chemotaxis, cell proliferation, migration, and gene expression. Accumulating evidence suggests that the CXCL12/CXCR4/CXCR7 axis plays a pivotal role in tumor development, survival, angiogenesis, metastasis, and tumor microenvironment. In addition, this chemokine axis promotes chemoresistance in cancer therapy via complex crosstalk with other pathways. Multiple small molecules targeting CXCR4/CXCR7 have been developed and used for preclinical and clinical cancer treatment. In this review, we describe the roles of the CXCL12/CXCR4/CXCR7 axis in cancer progression and summarize strategies to develop novel targeted cancer therapies.

CXCR4 and CCR7: Two eligible targets in targeted cancer therapy

Cancer is one of the most common cause of death in the world with high negative emotional, economic, and social impacts. Conventional therapeutic methods, including chemotherapy and radiotherapy, have not proven satisfactory and relapse is common in most cases. Recent studies have focused on targeted therapy with more precise identification and targeted attacks to the cancer cells. For this purpose, chemokine receptors are proper targets and among them, CXCR4 and CCR7, with a crucial role in cancer metastasis, are being considered as desired candidates for investigation. In this review paper, the most important experimental results are highlighted on the potential targeted therapies based on CXCR4 and CCR7 chemokine receptors.