Expression and purification of functional PDGF receptor beta

The role of CD146 in renal disease: from experimental nephropathy to clinics

Vascular endothelial dysfunction is a major risk factor in the development of renal diseases. Recent studies pointed out a major interest for the inter-endothelial junction protein CD146, as its expression is modulated during renal injury. Indeed, some complex mechanisms involving this adhesion molecule and its multiple ligands are observed in a large number of renal diseases in fundamental or clinical research. The purpose of this review is to summarize the most recent literature on the role of CD146 in renal pathophysiology, from experimental nephropathy to clinical trials.

PDGF-D Prodomain Differentially Inhibits the Biological Activities of PDGF-D and PDGF-B

As a member of PDGF/VEGF (Platelet-derived growth factor/ Vascular endothelial growth factor) growth factors, PDGF-D regulates blood vessel development, wound healing, innate immunity, and organogenesis. Unlike PDGF-A and PDGF-B, PDGF-D has an additional CUB (Complement C1r/C1s, Uegf, Bmp1) domain at the N-terminus of its growth factor domain, and thus it is secreted in a latent, inactive complex, which needs to be proteolytically activated for its biological activities. However, how the CUB domain contributes to the latency and activation of the growth factor remains elusive. In this study, we modeled the dimeric structure of PDGF-D pro-complex and studied the inhibitory functions of PDGF-D prodomain on PDGF-B and PDGF-D signaling. In our model, the growth factor domain of PDGF-D forms a VEGF-D-like dimer through their β1 and β3 interactions. The hinge and CUB domains of PDGF-D bind at the opposite sides of the growth factor domain and exclude the PDGFR-β (PDGF Receptor β) D2 and D3 domains from recognizing the growth factor. In addition, we verified that PDGF-D prodomain could inhibit both PDGF-B and PDGF-D mediated PDGFR-β transphosphorylation in a dose-dependent manner. However, PDGF-D prodomain could only inhibit the proliferation of NIH 3T3 cells stimulated by PDGF-D but not by PDGF-B, indicating its differential inhibitory activities toward PDGF-B and PDGF-D signaling.

Recent advances in, and challenges of, anti-angiogenesis agents for tumor chemotherapy based on vascular normalization

A major problem associated with cancer treatment is resistance-prone chemotherapeutic drugs. An increasing number of studies have documented that the occurrence of resistance tends to be associated with abnormal blood vessels. In 2001, Jain proposed the vascular normalization theory, which was recently applied to the drug-resistant treatment of tumors in the clinic. Through the intervention of angiogenesis inhibitors, remodeling the structure and function of abnormal vessels can maximize the efficacy of chemotherapeutic drugs. In this review, we systematically describe the occurrence and progress of tumor angiogenesis, as well as the pathological characteristics of tumor blood vessels. Moreover, druggable targets for vascular normalization and the development of related inhibitors are also outlined.

Identification of a Novel CSNK2A1-PDGFRB Fusion Gene in a Patient with Myeloid Neoplasm with Eosinophilia

Platelet-derived growth factor receptor beta (PDGFRB) rearrangements play an important role in the pathogenesis of eosinophilia-associated myeloid/lymphoid neoplasms. Up to now, more than 70 PDGFRB fusions have been identified. Here, a novel PDGFRB fusion gene CSNK2A1-PDGFRB has been identified in myeloproliferative neoplasm (MPN) with eosinophilia by RNA-sequencing, which has been verified by reverse transcription polymerase chain reaction and Sanger sequencing. The new PDGFRB fusion partner gene CSNK2A1 encoded one of the two catalytic subunit of casein kinase II (CK2). To our knowledge, this is the first report on the involvement of CSNK2A1 in fusion genes, especially fusion with another kinase PDGFRB in MPN. In addition, the CSNK2A1-PDGFRB fusion retained the entire kinase domain of PDGFRB and response to imatinib at low concentration. The patient with CSNK2A1-PDGFRB was sensitive to imatinib treatment and acquired sustained complete remission.

CD146, from a melanoma cell adhesion molecule to a signaling receptor

CD146 was originally identified as a melanoma cell adhesion molecule (MCAM) and highly expressed in many tumors and endothelial cells. However, the evidence that CD146 acts as an adhesion molecule to mediate a homophilic adhesion through the direct interactions between CD146 and itself is still lacking. Recent evidence revealed that CD146 is not merely an adhesion molecule, but also a cellular surface receptor of miscellaneous ligands, including some growth factors and extracellular matrixes. Through the bidirectional interactions with its ligands, CD146 is actively involved in numerous physiological and pathological processes of cells. Overexpression of CD146 can be observed in most of malignancies and is implicated in nearly every step of the development and progression of cancers, especially vascular and lymphatic metastasis. Thus, immunotherapy against CD146 would provide a promising strategy to inhibit metastasis, which accounts for the majority of cancer-associated deaths. Therefore, to deepen the understanding of CD146, we review the reports describing the newly identified ligands of CD146 and discuss the implications of these findings in establishing novel strategies for cancer therapy.

The role of PDGF-B/PDGFR-BETA axis in the normal development and carcinogenesis of the breast

PDGFs/PDGFRs axis is documented as an important tumor-promoting agent and potential therapeutic target for several human carcinomas, including breast cancer. However, little is known about the role played by the PDGF family members in the normal development of the breast tissue, breast carcinogenesis and tumor-microenvironment dynamics Despite its potent pro-lymphangiogenic effects, PDGF-B/PDGFR-beta axis remains controversial and incompletely elucidated in the field of breast cancer, with emphasis to its differential implications in breast cancer molecular subtypes. Although some data are available concerning this aspect, little or no information is found regarding the role of the PDGF-B/PDGFR-beta axis in rare and aggressive types of breast cancers, such as triple negative breast cancers (TNBCs) and its associated subtypes This review attempted to gather as many data as possible concerning PDGFs family members in the normal breast tissue and in breast carcinogenesis with special focus on their role in diagnosis and therapeutic approach.