Phase II clinical trial of multiple peptide vaccination for advanced head and neck cancer patients revealed induction of immune responses and improved OS.

PURPOSE: The peptides derived from ideal cancer-testis antigens, including LY6K, CDCA1, and IMP3 (identified using genome-wide cDNA microarray analyses), were used in immunotherapy for head and neck squamous cell cancer (HNSCC). In this trial, we analyzed the immune response to and safety and efficacy of vaccine therapy. EXPERIMENTAL DESIGN: A total of 37 patients with advanced HNSCC were enrolled in this trial of peptide vaccine therapy, and the OS, PFS, and immunologic response were evaluated using enzyme-linked ImmunoSpot (ELISPOT) and pentamer assays. The peptides were subcutaneously administered weekly with IFA. The primary endpoints were evaluated on the basis of differences between HLA-A*2402-positive [A24(+)] patients treated with peptide vaccine therapy and -negative [A24(-)] patients treated without peptide vaccine therapy among those with advanced HNSCC. RESULTS: Our cancer vaccine therapy was well tolerated. The OS of the A24(+) vaccinated group (n = 37) was statistically significantly longer than that of the A24(-) group (n = 18) and median survival time (MST) was 4.9 versus 3.5 months, respectively; P < 0.05. One of the patients exhibited a complete response. In the A24(+) vaccinated group, the ELISPOT assay identified LY6K-, CDCA1-, and IMP3-specific CTL responses in 85.7%, 64.3%, and 42.9% of the patients, respectively. The patients showing LY6K- and CDCA1-specific CTL responses demonstrated a longer OS than those without CTL induction. Moreover, the patients exhibiting CTL induction for multiple peptides demonstrated better clinical responses. CONCLUSIONS: The immune response induced by this vaccine may improve the prognosis of patients with advanced HNSCC.

A low Dicer expression is associated with resistance to 5-FU-based chemoradiotherapy and a shorter overall survival in patients with oral squamous cell carcinoma.

BACKGROUND: The deregulation of microRNA (miRNA) is associated with multiple processes involved in cancer progression. RNase III endonucleases, Dicer and Drosha, are key enzymes for miRNA biogenesis, and it has been reported that altered expressions of these molecules affect the clinical outcomes of patients with various cancers. However, the clinical value of measuring the levels of Dicer and Drosha in oral squamous cell carcinoma (OSCC) patients is unclear. The purpose of this study was to determine the clinical significance of the expressions of Dicer and Drosha in patients with OSCC. METHODS: Oral squamous cell carcinoma specimens were obtained from 61 patients who underwent surgery following 5-fluorouracil-based chemoradiotherapy at Kumamoto University Hospital between October 2003 and January 2009. Paraffin-embedded sections obtained from biopsy specimens were immunohistochemically analyzed. The associations between Dicer, Drosha, and various clinicopathological features were examined, and the effects of Dicer and Drosha on the prognosis were evaluated. RESULTS: A low Dicer tumor expression was significantly correlated with the pathological response to chemoradiotherapy. Furthermore, a Cox regression analysis based on the overall survival revealed the Dicer expression status (hazard ratio, 0.34; P = 0.048) and pathological response to chemoradiotherapy (hazard ratio, 0.21; P = 0.014) to be significant prognostic factors in OSCC patients. On the other hand, the Drosha expression was not associated with any clinicopathological features or the prognosis. CONCLUSION: These results suggest that Dicer is a potential biomarker for predicting the clinical response to 5-FU-based chemoradiotherapy and the overall survival in patients with OSCC.

Selective inhibition of nuclear factor-κB by nuclear factor-κB essential modulator-binding domain peptide suppresses the metastasis of highly metastatic oral squamous cell carcinoma.

Nuclear factor-κB (NF-κB) activation contributes to the development of metastasis, thus leading to a poor prognosis in many cancers, including OSCC. However, little in vivo experimental data are available about the effects of NF-κB inhibition on OSCC metastasis. OSCC sublines were established from a GFP-expressing parental cell line, GSAS, and designated GSAS/N3 and N5 according to the in vivo passage number after cervical lymph node metastasis by a serial orthotopic transplantation model. In vitro migration and invasion were assessed in these cells, and the NF-κB activities and expression of NF-κB-regulated metastasis-related molecules were also examined. In in vivo experiments, the metastasis and survival of tumor-engrafted mice were monitored. Furthermore, the effects of a selective NF-κB inhibitor, NEMO-binding domain (NBD) peptide, on metastasis in GSAS/N5-engrafted mice were assessed, and engrafted tongue tumors were immunohistochemically examined. Highly metastatic GSAS/N3 and N5 cells showed an enhanced NF-κB activity, thus contributing to increased migration, invasion, and a poor prognosis compared with the parent cells. Furthermore, the expression levels of NF-κB-regulated metastasis-related molecules, such as fibronectin, ß1 integrin, MMP-1, -2, -9, and -14, and VEGF-C, were upregulated in the highly metastatic cells. The NBD peptide suppressed metastasis and tongue tumor growth in GSAS/N5-inoculated mice, and was accompanied by the downregulation of the NF-κB-regulated metastasis-related molecules in engrafted tongue tumors. Our results suggest that the selective inhibition of NF-κB activation by NBD peptide may provide an effective approach for the treatment of highly metastatic OSCC.

Involvement of NF-kappaB-mediated maturation of ADAM-17 in the invasion of oral squamous cell carcinoma.

The involvement of a disintegrin and metalloprotease domain (ADAM)-17 on the cancer invasion was investigated in oral squamous cell carcinoma (OSCC) cells. TNFalpha induced the conversion from the proform of ADAM-17 to its mature form time-dependently. TNFalpha also cleaved CD44 to its small fragments, as observed by a Western blot analysis. The transfection of ADAM-17 siRNA partially suppressed the expression of ADAM-17 as well as the cleavage of CD44. On the other hand, TNFalpha activated a transcription factor NF-kappaB in OSCC cells, while NBD peptide, an NF-kappaB inhibitor, inhibited the ADAM-17 maturation, thus suggesting that NF-kappaB is involved in ADAM-17 maturation. Moreover, an in vitro invasion assay revealed that both ADAM-17 siRNA and NBD peptides strongly suppressed the TNFalpha-induced invasion of OSCC cells through the matrix. In conclusion, ADAM-17 plays an important role in cancer invasion probably through CD44 cleavage.

ADAM-17 associated with CD44 cleavage and metastasis in oral squamous cell carcinoma.

ADAM-17 (a disintegrin and metalloproteinase 17) is a membrane-anchored protein, which can cleave the ectodomain in a variety of transmembrane proteins. In the in vitro experiments with tumor cells, ADAM-17 is reported to cleave CD44, an adhesion molecule that interacts with hyaluronic acid, to promote tumor cell migration. In the present study, we examined ADAM-17 expression and CD44 cleavage in specimens from 50 patients diagnosed to have oral squamous cell carcinoma (SCC). Each specimen was divided into two pieces, one was studied by immunohistochemistry and the other was subjected to a Western blot. By coordinating the results of both analyses, ADAM-17 expression was evaluated to be high in 23 cases (46%). When CD44 cleavage was also studied by immunohistochemical staining as well as with Western blotting, CD44 cleavage was judged to be positive in 29 cases (58%). When the ADAM-17 expression level was compared with the CD44 cleavage state, most of the cases expressing high levels of ADAM-17 (87%) showed positive CD44 cleavage. The level of ADAM-17 expression was significantly correlated to the nodal metastasis and local recurrence in oral SCC. Our findings suggest that ADAM-17 is involved in CD44 cleavage and contributes to tumor progression in oral SCC.