ABSTRACT
With the development of technologies that can transform immune cells into therapeutic modalities, immunotherapy has remarkably changed the current paradigm of cancer treatment in recent years. NK cells are components of the innate immune system that act as key regulators and exhibit a potent tumor cytolytic function. Unlike T cells, NK cells exhibit tumor cytotoxicity by recognizing non-self, without deliberate immunization or activation. Currently, researchers have developed various approaches to improve the number and anti-tumor function of NK cells. These approaches include the use of cytokines and Abs to stimulate the efficacy of NK cell function, adoptive transfer of autologous or allogeneic ex vivo expanded NK cells, establishment of homogeneous NK cell lines using the NK cells of patients with cancer or healthy donors, derivation of NK cells from induced pluripotent stem cells (iPSCs), and modification of NK cells with cutting-edge genetic engineering technologies to generate chimeric Ag receptor (CAR)-NK cells. Such NK cell-based immunotherapies are currently reported as being promising anti-tumor strategies that have shown enhanced functional specificity in several clinical trials investigating malignant tumors. Here, we summarize the recent advances in NK cell-based cancer immunotherapies that have focused on providing improved function through the use of the latest genetic engineering technologies. We also discuss the different types of NK cells developed for cancer immunotherapy and present the clinical trials being conducted to test their safety and efficacy.
ABSTRACT
Rat hippocampal precursor cells isolated from hippocampi of embryonic day 16.5 (E16.5) rat embryos were found to proliferate in the presence of basic fibroblast growth factor. Addition of soluble neural cell adhesion molecule (NCAM) to these precursor cells reduced cell proliferation in a dose dependent manner and enhanced the induction of precursor cells' differentiation to the neuronal lineage. Given these findings that NCAM induces the differentiation of hippocampal precursor cells, we investigated possible effects of NCAM on the expression of basic helix-loop-helix (bHLH) transcription factors during the differentiation. Soluble NCAM upregulated the transcription of bHLH transcription factors, neurogenin1 and NeuroD, but decreased HES5. Western blot analysis showed that NCAM increased the expression levels of CaMKII, p-MAPK, GluR1 and NR1 but decreased p-STAT3. These results support a role for NCAM in the inhibition of proliferation and the induction of neural differentiation of hippocampal neural precursor cells, and act as developmental regulators of the bHLH families, ultimately leading to the generation of glutamatergic neural cell types in the differentiation of hippocampal precursor cells.