Pivotal role of CD38 biomarker in combination with CD24, EpCAM, and ALDH for identification of H460 derived lung cancer stem cells.

Lung cancer is the number one killer among all cancers and is estimated to kill over 170,000 individual in 2010 in the United States. However, little is understood about the role of tumor initiating cells in the lung cancer and whether these cells play a major role in initiation, drug resistance, and metastases of this disease. We have isolated lungospheres from tumors grown in mice and have critically examined proposed biomarkers of lung cancer stem cells such as ALDH, EpCAM, CD133/1, CD133/2, CD24, and CD38, using global gene expression, flow cytometric analysis, and quantitative real time PCR. We present evidences that the pattern of overexpression of ALDH and EpCAM, two widely discussed biomarkers of cancer stem cells, in the tumor generated by lung cancer stem cells in mice are different that could be an indicative of tumor aggressiveness. We propose, for the first time, that CD38 in combination with CD24 is a biomarkers for H460 derived lung cancer stem cells and could be used to elucidate the characteristics of these sub-population of cells. Our results demonstrate that the combination of CD24(Low/-)/CD38+ and overexpression of ALDH1 and EpCAM is the signature of enriched tumor initiating cells in H460 non-small cell lung cancer cell line. Our results propose H460-derived cancer stem cells as a well defined cell for future comprehensive analysis of putative lung cancer stem cells-like cells.

The stability of breast cancer progenitor cells during cryopreservation: Maintenance of proliferation, self-renewal, and senescence characteristics.

Cancer stem cells are believed to be the driving force behind tumor progression and development. Despite extensive studies on the effects of cryopreservation on embryonic and hematopoietic stem cells there is only limited data that directly deals with in the cryopreservation of cancer stem cells. In this study, we looked at the effect of cryopreservation on breast cancer progenitor cells known as mammospheres, which are derived from the MCF7 breast carcinoma cell line. We focused on the effect of cryopreservation on the cell biology and function of tumor-initiating cells using a standard method of cryopreservation with 15% dimethyl sulfoxide (Me(2)SO). Cell proliferation and survival was analyzed by alamarBlue solution on cryopreserved cells stored for 1-12 weeks and also by the expression of Ki-67. To assess self-renewal, single cells were harvested by limiting dilution procedure and wells were scored once a week. In order to investigate senescence, the activity of beta-galactosidase was detected by histochemical staining. Our results indicate that cryopreservation of breast cancer initiating cells will not reduce the ability of the cells to proliferate following cryopreservation storage for up to 12 months. Similarly, self-renewal, a unique property of stem cells, was shown to be maintained during cryopreservation. In contrast, cryopreservation of the mammospheres significantly increases the rate of senescence-mediated pathways. These data suggest that although cryopreservation of tumor-initiating cells is feasible but further studies are necessary to achieve a trustable repository of tumor-initiating cells and the design of new therapeutic measures to specifically target these cells.

Phase II study of belagenpumatucel-L, a transforming growth factor beta-2 antisense gene-modified allogeneic tumor cell vaccine in non-small-cell lung cancer.

PURPOSE: Belagenpumatucel-L is a nonviral gene-based allogeneic tumor cell vaccine that demonstrates enhancement of tumor antigen recognition as a result of transforming growth factor beta-2 inhibition. PATIENTS AND METHODS: We performed a randomized, dose-variable, phase II trial involving stages II, IIIA, IIIB, and IV non-small-cell lung cancer patients. Each patient received one of three doses (1.25, 2.5, or 5.0 x 10(7) cells/injection) of belagenpumatucel-L on a monthly or every other month schedule to a maximum of 16 injections. Immune function, safety, and anticancer activity were monitored. RESULTS: Seventy-five patients (two stage II, 12 stage IIIA, 15 stage IIIB, and 46 stage IV patients) received a total of 550 vaccinations. No significant adverse events were observed. A dose-related survival difference was demonstrated in patients who received > or = 2.5 x 10(7) cells/injection (P = .0069). Focusing on the 61 late-stage (IIIB and IV) assessable patients, a 15% partial response rate was achieved. The estimated probabilities of surviving 1 and 2 years were 68% and 52%, respectively for the higher dose groups combined and 39% and 20%, respectively, for the low-dose group. Immune function was explored in the 61 advanced-stage (IIIB and IV) patients. Increased cytokine production (at week 12 compared with patients with progressive disease) was observed among clinical responders (interferon gamma, P = .006; interleukin [IL] -6, P = .004; IL-4, P = .007), who also displayed an elevated antibody-mediated response to vaccine HLAs (P = .014). Furthermore, positive enzyme-linked immunospot reactions to belagenpumatucel-L showed a correlation trend (P = .086) with clinical responsiveness in patients achieving stable disease or better. CONCLUSION: Belagenpumatucel-L is well tolerated, and the survival advantage justifies further phase III evaluation.