Utilization of invariant natural killer T cells for gastric cancer treatment

The role of NKT cells in gastrointestinal cancers

Gastrointestinal (GI) cancers represent a complex array of cancers that affect the digestive system. This includes liver, pancreatic, colon, rectal, anal, gastric, esophageal, intestinal and gallbladder cancer. Patients diagnosed with certain GI cancers typically have low survival rates, so new therapeutic approaches are needed. A potential approach is to harness the potent immunoregulatory properties of natural killer T (NKT) cells which are true T cells, not natural killer (NK) cells, that recognize lipid instead of peptide antigens presented by the non-classical major histocompatibility (MHC) molecule CD1d. The NKT cell subpopulation is known to play a vital role in tumor immunity by bridging innate and adaptive immune responses. In GI cancers, NKT cells can contribute to either antitumor or protumor immunity depending on the cytokine profile expressed and type of cancer. This review discusses the complexities of the role of NKT cells in liver, colon, pancreatic and gastric cancers with an emphasis on type I NKT cells.

Percentage of Natural Killer (NK) Cells in Peripheral Blood Is Associated with Prognosis in Patients with Gastric Cancer: A Retrospective Study from a Single Center

Background

Natural killer (NK) cells are important for the prognosis of multiple cancers, but their prognostic value remains to be evaluated in patients with gastric cancer. Thus, this retrospective study was conducted at a single center to investigate the association between percentage of NK cells in the peripheral blood and prognosis in patients with gastric cancer.

Material/Methods

The data of 180 gastric cancer patients were collected. Univariate and multivariate Cox regression models were applied to screen candidate prognostic factors. A time-dependent receiver operating characteristic curve was employed to evaluate the ability of NK cells as a prognostic marker. Furthermore, we determined the correlation between the NK cells percentage and other parameters and their clinical significance.

Results

Patients with a higher percentage of NK cells survived longer than those with a lower percentage of NK cells. Cox analysis revealed that NK cells could be used as an independent indicator for patients with gastric cancer. The percentage of NK cells was positively correlated with lymphocyte count and albumin, but was negatively correlated with CA125 and neutrophil-lymphocyte ratio. The area under the curve for NK cells in predicting the 5-year survival rate for gastric cancer was 0.792. This increased to 0.830 upon combining NK cells with neutrophil-lymphocyte ratio. Patients at early T, N, and clinical stages possessed a significantly higher percentage of NK cells compared to those at advanced T, N, and clinical stages of gastric cancer.

Conclusions

Our results suggest that a higher percentage of NK cells predicts is associated with longer survival of gastric cancer patients and could serve as an independent prognostic biomarker.