Adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type 1 (HTLV-1) infection, occurs in 2% to 4% of the HTLV-1 carriers with a long latent period, suggesting that additional alterations participate in the development of ATL. To characterize and identify novel markers of ATL, we examined the expression profiles of more than 12 000 genes in 8 cases of acute-type ATL using microarray. One hundred ninety-two genes containing interleukin 2 (IL-2) receptor ␣ were up-regulated more than 2-fold compared with CD4 ؉ and CD4 ؉ CD45RO ؉ T cells, and tumor suppressor in lung cancer 1 (TSLC1), caveolin 1, and prostaglandin D2 synthase showed increased expression of more than 30-fold.

We suggest that gammadelta T-cell immunotherapy might be safe and feasible for patients with recurrent non-small-cell lung cancer.

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Human γδ T cells can recognize and kill non-small cell lung cancer (NSCLC) cells using the Vγ9Vδ2 T-cell receptor and/or NKG2D. We have established clinical grade large-scale ex vivo expansion of γδ T cells from peripheral blood mononuclear cells by culturing with zoledronate and interleukin-2 (IL-2). A phase I study was conducted to evaluate safety and potential antitumor effects of re-infusing ex vivo expanded γδ T cells in patients with recurrent or advanced NSCLC. Patient's peripheral blood mononuclear cells were stimulated with zoledronate (5 μM) and IL-2 (1000 IU/mL) for 14 days. Harvested cells, mostly γδ T cells, were given intravenously every 2 weeks without additional IL-2, a total of 6 times. The cumulative number of transferred γδ T cells ranged from 2.6 to 45.1 x 10⁹ (median, 15.7×10⁹). Fifteen patients underwent adoptive immunotherapy with these γδ T cells. There were no severe adverse events related to the therapy. Immunomonitoring data showed that with increasing numbers of infusions, the number of peripheral γδ T cells gradually increased. All patients remained alive during the study period with a median survival of 589 days and median progression-free survival of 126 days. According to the Response Evaluation Criteria In Solid Tumors, there were no objective responses. Six patients had stable disease, whereas the remaining 6 evaluable patients experienced progressive disease 4 weeks after the sixth transfer. We conclude that adoptive transfer of zoledronate-expanded γδ T cells is safe and feasible in patients with NSCLC, refractory to other treatments.

We recently identified TSLC1, a tumor suppressor gene in human lung cancer. Gene silencing by promoter methylation has been observed frequently in adenocarcinoma of the lung, liver, and pancreas. Here, we demonstrate that TSLC1 expression is also absent or markedly reduced in 3 of 4 prostate cancer cell lines. Promoter sequences of TSLC1 were heavily methylated in PPC-1 cells that lacked TSLC1 expression, supporting the idea that promoter methylation is strongly correlated with complete loss of gene expression. Promoter sequences of TSLC1 were also methylated significantly in 7 of 22 (32%) primary prostate cancers. Hypermethylation of the promoter occurred not only in advanced tumors, but also in relatively early-stage tumors. Restoration of TSLC1 expression substantially suppressed tumor formation of PPC-1 cells in nude mice. These findings indicate that alteration of TSLC1 is involved in prostate cancer.