Induction of Immunological Antitumor Effects by the Combination of Adenovirus-Mediated Gene Transfer of B7-1 and Anti-Programmed Cell Death-1 Antibody in a Murine Squamous Cell Carcinoma Model.

BACKGROUND: The goal of this study was to evaluate the antitumor immune effects of B7-1 gene expression in addition to immune checkpoint inhibitor against squamous cell carcinoma. METHODS: A murine SCC cell line, KLN205, was infected with adenoviral vector carrying B7-1 (AdB7). Infected cells were injected subcutaneously in the flanks of DBA/2 mice. Three weeks after implantation, anti-mouse PD-1 antibody (antiPD1) was intraperitonially administrated twice a week for a total of six times. RESULTS: CD80 was significantly overexpressed in the AdB7-infected tumors. IFN-gamma in the T cells in the spleen was significantly increased and tumor size was significantly reduced in the mice treated with both AdB7 and antiPD1. Targeted tumors treated with both AdB7 and antiPD1 exhibited significantly increased cell densities of total immune cells as well as Ki-67+ CD8+ T cells and decreased regulatory T cells. CONCLUSIONS: These results suggest that the B7-1 gene transfer may enhance the antitumor effect of anti-PD1 antibody against SCC.

Oncolytic effect of Midkine promoter-based conditionally replicating adenoviruses expressing EGFR siRNA in head and neck squamous cancer cell line T891.

BACKGROUND: Epidermal growth factor receptor (EGFR) is overexpressed in head and neck squamous cell carcinomas (HNSCCs). Midkine expression is restricted in adult tissues but is increased in several malignant tumors, including HNSCCs. AIM: Here, we evaluated the antitumor effect of Midkine promoter-based conditionally replicative adenovirus expressing siRNA against EGFR for targeting HNSCCs expressing Midkine. METHODS AND RESULTS: A conditionally replicative adenovirus vector controlled by the Midkine promoter, Ad-MK-siEGFR, was generated by integrating gene-expressing siRNA against EGFR. Antitumor effect of Ad-MK-siEGFR was tested in vitro using established HNSCC cell line, T891 with strong Midkine expression. Expression of EGFR in T891 infected with Ad-MK-siEGFR was significantly lower than that of T891 infected with control. Cytotoxicity assays showed significant growth suppression of Ad-MK-siEGFR in T891 cells. CONCLUSIONS: This study demonstrated the possibility of oncolytic therapy using the Midkine promoter-based conditional replication-selective adenovirus containing siRNA against EGFR in HNSCC cell line T891. Further validation of the findings in more cell lines and in vivo should be performed to clarify the potential clinical application.

Adenovirus-mediated transfer of HPV 16 E6/E7 antisense RNA combined with cisplatin inhibits cellular growth and induces apoptosis in HPV-positive head and neck cancer cells.

Human papillomavirus (HPV) infection has been identified as an etiologic factor of head and neck cancers (HNCs). We explored the potential use of antisense HPV RNA transcripts for gene therapy and its effect in combination with cisplatin (CDDP) for HPV-positive HNCs. We introduced the antisense RNA transcripts of the E6 and E7 genes of HPV type 16 into UM-SCC-47 cells harboring HPV 16 and YCU-T892 cells that were HPV-negative using a recombinant adenoviral vector, Ad-E6/E7-AS. We then analyzed the effects of the introduction of Ad-E7-AS on cell and tumor growth and the synergistic effect with CDDP in vitro and in vivo. After infection of Ad-E6/E7-AS, the cellular growth of UM-SCC-47 cells were suppressed, but not that of YCU-T892 cells. E7 protein expression was suppressed, and p53 and pRb protein expression increased after infection of Ad-E7-AS. Cell growth and tumorigenicity were greatly suppressed in combination with CDDP compared with Ad-E7-AS or CDDP treatment alone in vitro. Ad-E7-AS combined with CDDP treatment significantly reduced the volumes of established subcutaneous tumors. Transfection with HPV 16 E7 antisense RNA combined with CDDP treatment might be a potentially useful approach to the therapy of HPV 16-positive HNC.

Impact of alcohol dehydrogenase-aldehyde dehydrogenase polymorphism on clinical outcome in patients with hypopharyngeal cancer.

BACKGROUND: The purpose of this research was to investigate the association between alcohol dehydrogenase 1B (ADH1B) and aldehyde dehydrogenase 2 (ALDH2) polymorphisms and hypopharyngeal squamous cell carcinoma (SCC) survival. METHODS: We genotyped ADH1B (rs1229984) and ALDH2 (rs671) single nucleotide polymorphisms (SNPs) in 85 Japanese male patients with hypopharyngeal SCC. The independent prognostic values of ADH1B-ALDH2 genotypes were analyzed by univariate and multivariate proportional hazard Cox regression, taking well-known clinical risk factors into account. RESULTS: Heavy drinkers with ALDH2*2 allele resulted in significantly worse overall survival (OS; P = .028) and disease-free survival (DFS; P = .029) compared with other patients. Heavy drinkers with ALDH2*2 allele remained statistically significant in multivariate analysis for OS and DFS, indicating independent poor prognostic factor (hazard ratio [HR] 2.251; 95% confidence interval [CI] 1.018-4.975 and HR 2.261; 95% CI 1.021-5.006, respectively). CONCLUSION: We conclude that heavy drinkers with the ALDH2*2 allele are associated with poor outcome in hypopharyngeal SCC.

Prognostic value of ALDH2 polymorphism for patients with oropharyngeal cancer in a Japanese population.

BACKGROUND: Half of Japanese possess a polymorphism of aldehyde dehydrogenase 2(ALDH2), while few white individuals possess this mutation. The purpose of this study was to investigate the possibility of ALDH2 polymorphism as a prognostic factor for oropharyngeal cancer (OPC) among Japanese population. METHODS: We analyzed 82 Japanese patients with OPC treated between 2006 and 2011. The median observation period was 50 months. P16-staining and ALDH2 polymorphisms were investigated. To examine the frequencies of second primary pharyngeal and esophageal cancers (SPPEC),37 Japanese patients with OPC treated at Tokyo University Hospital were included for statistical analysis. RESULTS: Statistically significant differences were noted in OS among sex, age, N classification, and p16 (p = 0.045, 0.024, 0.020, 0.007, respectively). In addition, OS and DSS rates of the patients with heterozygous ALDH2 tended to be worse than those of the patients with homozygous ALDH2 (p = 0.21, 0.086, respectively). Of note, OS and DSS of the patients with p16-negative OPC and heterozygous ALDH2 was significant poorer than those of the patients with p16-positive OPC (p = 0.002, 0.006, respectively), while there was no significant difference in OS and DSS between patients with p16-positive OPC and patients with p16-negative OPC and homozygous ALDH2. CONCLUSIONS: ALDH2 polymorphism might be a promising prognostic factor for Japanese patients with p16-negative OPC.

Expression of amphiregulin in mucoepidermoid carcinoma of the major salivary glands: a molecular and clinicopathological study.

In mucoepidermoid carcinoma (MEC), CRTC1-MAML2 fusion indicates a favorable prognosis. Amphiregulin (AREG), an epidermal growth factor receptor (EGFR) ligand, has been shown to be a downstream target of CRTC1-MAML2 fusion, and to play a role in tumor growth and survival in CRTC1-MAML2-positive MEC cell lines. The aim of this study was to characterize the AREG and EGFR expression in the fusion-positive and fusion-negative MEC of the major salivary gland. The AREG and EGFR expression were studied by immunochemistry in 33 MEC cases of the major salivary glands. CRTC1-MAML2 fusion was tested by reverse-transcription polymerase chain reaction (23 CRTC1-MAML2 fusion-positive, 10 fusion-negative). Of 23 fusion-positive cases, AREG and EGFR overexpression were detected in 17 (73.9%) and 14 (60.9%) cases, respectively. Of 10 fusion-negative cases, AREG and EGFR overexpression were detected in 1 (10%) and 3 (30.0%) cases, respectively. There was a positive correlation between CRTC1-MAML2 fusion and AREG overexpression (P < .01), but not between CRTC1-MAML2 fusion and EGFR overexpression. The AREG overexpression was associated with a longer disease-free survival of the MEC patients (P = .042), but EGFR overexpression was not. In this study, we showed that AREG overexpression was detected more frequently in the CRTC1-MAML2 fusion-positive tumors than in fusion-negative tumors. Detection of AREG expression may be useful for identifying CRTC1-MAML2-positive MECs and as a marker for favorable prognosis.

Reactions of Lotus japonicus ecotypes and mutants to root parasitic plants.

Witchweeds (Striga spp.) and broomrapes (Orobanche spp.) are obligate root parasitic plants on economically important field and horticultural crops. The parasites' seeds are induced to germinate by root-derived chemical signals. The radicular end is transformed into a haustorium which attaches, penetrates the host root and establishes connection with the vascular system of the host. Reactions of Lotus japonicus, a model legume for functional genomics, were studied for furthering the understanding of host-parasite interactions. Lotus japonicus was compatible with Orobanche aegyptiaca, but not with Orobanche minor, Striga hermonthica and Striga gesnerioides. Orobanche minor successfully penetrated Lotus japonicus roots, but failed to establish connections with the vascular system. Haustoria in Striga hermonthica attached to the roots, but penetration and subsequent growth of the endophyte in the cortex were restricted. Striga gesnerioides did not parasitize Lotus japonicus. Among seven mutants of Lotus japonicus (castor-5, har1-5, alb1-1, ccamk-3, nup85-3, nfr1-3 and nsp2-1) with altered characteristics in relation to rhizobial nodulation and mycorrhizal colonization, castor-5 and har1-5 were parasitized by Orobanche aegyptiaca with higher frequency than the wild type. In contrast, Orobanche aegyptiaca tubercle development was delayed on the mutants nup85-3, nfr1-3 and nsp2-1. These results suggest that nodulation, mycorrhizal colonization and infection by root parasitic plants in Lotus japonicus may be modulated by similar mechanisms and that Lotus japonicus is a potential model legume for studying plant-plant parasitism.