ABSTRACT
BACKGROUND: Adoptive natural killer (NK) cell transfer is being increasingly used as cancer treatment. However, clinical responses have so far been limited to patients with hematological malignancies. A potential limiting factor in patients with solid tumors is defective homing of the infused NK cells to the tumor site. Chemokines regulate the migration of leukocytes expressing corresponding chemokine receptors. Various solid tumors, including renal cell carcinoma (RCC), readily secrete ligands for the chemokine receptor CXCR2. We hypothesize that infusion of NK cells expressing high levels of the CXCR2 chemokine receptor will result in increased influx of the transferred NK cells into tumors, and improved clinical outcome in patients with cancer. METHODS: Blood and tumor biopsies from 14 primary RCC patients were assessed by flow cytometry and chemokine analysis. Primary NK cells were transduced with human CXCR2 using a retroviral system. CXCR2 receptor functionality was determined by Calcium flux and NK cell migration was evaluated in transwell assays. RESULTS: We detected higher concentrations of CXCR2 ligands in tumors compared with plasma of RCC patients. In addition, CXCL5 levels correlated with the intratumoral infiltration of CXCR2-positive NK cells. However, tumor-infiltrating NK cells from RCC patients expressed lower CXCR2 compared with peripheral blood NK cells. Moreover, healthy donor NK cells rapidly lost their CXCR2 expression upon in vitro culture and expansion. Genetic modification of human primary NK cells to re-express CXCR2 improved their ability to specifically migrate along a chemokine gradient of recombinant CXCR2 ligands or RCC tumor supernatants compared with controls. The enhanced trafficking resulted in increased killing of target cells. In addition, while their functionality remained unchanged compared with control NK cells, CXCR2-transduced NK cells obtained increased adhesion properties and formed more conjugates with target cells. CONCLUSIONS: To increase the success of NK cell-based therapies of solid tumors, it is of great importance to promote their homing to the tumor site. In this study, we show that stable engineering of human primary NK cells to express a chemokine receptor thereby enhancing their migration is a promising strategy to improve anti-tumor responses following adoptive transfer of NK cells.
Subject(s)
Carcinoma, Renal Cell/therapy , Genetic Engineering/methods , Kidney Neoplasms/therapy , Killer Cells, Natural/cytology , Receptors, Interleukin-8B/genetics , Adoptive Transfer , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/metabolism , Cell Line, Tumor , Cell Movement , Cells, Cultured , Chemokine CXCL5/metabolism , Female , Humans , Interleukin-8/metabolism , Kidney Neoplasms/genetics , Kidney Neoplasms/metabolism , Killer Cells, Natural/metabolism , Male , Receptors, Interleukin-8B/metabolismABSTRACT
OBJECTIVE: Tumour characteristics, preoperative work-up and surgical treatment in patients diagnosed with renal cell carcinoma (RCC) between 2005 and 2010, and changes over time were studied in a national population-based cohort. MATERIAL AND METHODS: The National Swedish Kidney Cancer Register (NSKCR) contains information on histopathology, Fuhrman grade and clinical stage at presentation, and on the preoperative work-up and surgical treatment of patients with RCC. Between 2005 and 2010, 5553 RCC patients were registered in the NSKCR, 99% of those registered in the National Cancer Registry. RESULTS: During the study period the mean tumour size decreased from 70 to 64 mm (p = 0.024) and the frequency of metastatic RCC decreased from 22% to 15% (p < 0.001). The use of preoperative chest computed tomography increased from 59% to 84%. In total, 4229 (76%) patients were treated with curative intent, 3453 (82%) underwent radical nephrectomy, 606 (14%) partial nephrectomy (PN) and 170 (4%) cryotherapy or radiofrequency ablation. In tumours up to 4 cm, PN was performed in 33% of the surgically treated patients. PN irrespective of size increased from 8% to 20% and laparoscopic nephrectomy increased from 6% to 17% during the period. In patients with metastatic RCC, 55% underwent cytoreductive nephrectomy. CONCLUSIONS: The NSKCR explores population-based data on the clinical handling of patients with RCC. This study, between 2005 and 2010, shows significant decrease in tumour size and metastatic RCC at presentation, a more complete preoperative work-up, and significantly increased use of PN and laparoscopic nephrectomy in Sweden.
