CD2 T-helper 17-like cells differentiated from a CD133 subpopulation of non-small cell lung carcinoma cells promote the growth of lung carcinoma.

Background: Cancer stem cells (CSCs) give rise to a diverse variety of differentiated cells, which comprise the bulk of the tumor microenvironment (TME). However, the exact multi-directional differentiation potential of CSCs has not been fully clarified. This study was designed to explore whether CSCs differentiate into cellular components of the TME to promote the growth of lung carcinoma.

Methods: The present of CD133, CD2, and CD133CD2 cells in both clinical lung adenocarcinoma tissue and non-small cell lung carcinoma (NSCLC) cell lines were monitored using polymerase chain reaction (PCR) Array, flow cytometry (FCM), quantitative real-time PCR (qRT-PCR) and immunohistofluorescence (IF). Stem-like properties of CD133 cells and CD2 cells were detected by sphere formation assay, IF, and western blot. Colony formation and xenograft tumors experiments were performed to assess the malignant behaviors of CD2 cells. The differentiation of CD133 cells to CD2 Th17-like cells was observed by FCM. The interleukin (IL)-2/phosphorylated signal transducer and activator of transcription protein 5 (pSTAT5)/retinoic acid receptor-related orphan receptor gamma t (RORγt) signaling pathway was evaluated by western blot and FCM.

Results: We found that CD133 cells within both clinical lung adenocarcinoma tissue and NSCLC cell lines included a subset of CD2-expressing cells, which were correlated with the grade of malignancy (r=0.7835, P<0.01) and exhibited stem-like properties. Then, we determined the tumorigenic effects of CD2 on the growth of transplanted Lewis lung carcinoma cells (LLC1) in C57/BL6 mice. The results indicated that CD2 cells were effective in promoting tumor growth (P<0.01). Furthermore, we obtained direct evidence of an ability of CD133 cells to transform to T-helper 17-like cells via an intermediate CD133CD2 progenitor cell that is able to secrete IL-17A and IL-23. Furthermore, we found that IL-2 can inhibit the production of T-helper 17-like cells (P<0.001) by modulating the activation of STAT5 signaling pathways to downregulate the expression of RORγt (P<0.001).

Conclusions: Our data demonstrates that Th17-like cells generated from CSCs support cancer progression. These findings enrich the definition of multidirectional differentiation potential of CSCs and improve the understanding of the role of CSCs in cancer progression, which aids the improvement and creation of therapies.