ABSTRACT
Src homology phosphotyrosyl phosphatase 2 (SHP2) is a protein tyrosine phosphatase encoded by PTPN11, which catalyzes the dephosphorylation of protein tyrosine. As a convergence node, SHP2 mediates multiple signaling pathways such as rat sarcoma (RAS)-rapidly accelerated fibrosarcoma (RAF)-mitogen-activated extracellular signal-regulated kinase (MEK)-extracellular regulated protein kinases (ERK), phosphatidylinositol 3-kinase (PI3K)-serine/threonine kinase (AKT), janus kinase (JAK)-signal transducer and activator of transcription (STAT) and programmed death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1). It can not only regulate the growth and proliferation of tumor cells, but also mediate the immune escape of tumor cells by influencing the tumor microenvironment. Given its dual biological functions in tumor immune regulation, SHP2 is a promising target for cancer immunotherapy. To date, several SHP2 allosteric inhibitors have been advanced into clinical trials for tumor immunotherapy with single or combination therapeutic strategies. Additionally, SHP2 activators also showed therapeutic potential in the field of tumor immune modulation. In this paper, we reviewed the dual function of SHP2 in both tumor and immune cells. Besides, the challenges and prospects of SHP2 modulators in cancer immunotherapy were also briefly discussed, aiming to explore new horizon of SHP2 modulators for tumor immunotherapy.
ABSTRACT
Macrophages are a major component of the tumor microenvironment (TME) of most tumors. They are characterized by a high degree of functional plasticity which enable these cells to both promote and eliminate established tumors. Under the influence of immunosuppressive TME, tumor infiltrating iNOS+ and CD11b+ M-1 effector macrophages get polarized towards tumor associated macrophages (TAM) which are tropic to variety of tumors. Increased infiltration and density of TAM is associated with tumor progression and poor prognosis in the plethora of tumors due to their angiogenetic and tissue re-modelling nature. Importantly, TAMs are also responsible for developing endothelium anergy, a major physical barrier for majority of cancer directed immune/chemotherapies. Therefore, functional retuning/re-educating TAM to M-1 phenotypic macrophages is paramount for effective immunotherapy against established tumors. In this review, we discuss and provide comprehensive update on TAM-targeted approaches for enhancing immunity against various solid tumors.
ABSTRACT
With 5-year survival rates remaining constant at 6% and rising incidences associated with an epidemic in obesity and metabolic syndrome, pancreatic ductal adenocarcinoma (PDAC) is on track to become the second most common cause of cancer-related deaths by 2030. The high mortality rate of PDAC stems primarily from the lack of early diagnosis and ineffective treatment for advanced tumors. During the past decade, the comprehensive atlas of genomic alterations, the prominence of specific pathways, the preclinical validation of such emerging targets, sophisticated preclinical model systems, and the molecular classification of PDAC into specific disease subtypes have all converged to illuminate drug discovery programs with clearer clinical path hypotheses. A deeper understanding of cancer cell biology, particularly altered cancer cell metabolism and impaired DNA repair processes, is providing novel therapeutic strategies that show strong preclinical activity. Elucidation of tumor biology principles, most notably a deeper understanding of the complexity of immune regulation in the tumor microenvironment, has provided an exciting framework to reawaken the immune system to attack PDAC cancer cells. While the long road of translation lies ahead, the path to meaningful clinical progress has never been clearer to improve PDAC patient survival.
