p53 Protein accumulation, cancer multiplicity, and aldehyde dehydrogenase-2 genotype in Japanese alcoholic men with early esophageal squamous cell carcinoma

Synchronous multiple intra-esophageal squamous cell carcinomas (SCCs) or oropharyngolaryngeal SCCs are common in alcoholics with esophageal SCC, and more frequently found in those with inactive heterozygous aldehyde dehydrogenase-2 (ALDH2). p53 alterations have been suspected as key molecular events in such multifocal esophageal carcinogenesis. We studied 95 Japanese alcoholic men with Tis and mucosal invasive esophageal SCC and found very high levels of p53 protein accumulation occurring in early esophageal SCC. Synchronous cancer multiplicity in the upper aerodigestive tract was found in 40 patients. p53 expression was not correlated with either cancer multiplicity or ALDH2 genotype. The risk for cancer multiplicity was associated with inactive heterozygous ALDH2 alone (OR=4.22) among the risk factors investigated, which also included smoking, less-active alcohol dehydrogenase-1B, and macrocytosis, enhancing the validity of the link between acetaldehyde exposure and cancer multiplicity.     

Colorectal cancer: genetics of development and metastasis

It has been well documented that there are two major pathways in colorectal carcinogenesis. One is the chromosomal instability pathway (adenoma–carcinoma sequence), which is characterized by allelic losses on chromosome 5q (APC), 17p (p53), and 18q (DCC/SMAD4), and the other is a pathway that involves microsatellite instability. Recent progress in molecular biology, however, has shown that colorectal carcinogenesis is not necessarily clearly divided into these two pathways, but is in fact more complicated. Other routes, including the transforming growth factor-β/SMAD pathway, the serrated pathway, and the epigenetic pathway, have been reported. Cross talk among these pathways has also been reported. In the invasion and metastasis steps of colorectal cancers, many more genes have now been identified as being involved in proteolysis, adhesion, angiogenesis, and cell growth. Recently accumulated evidence indicates that colorectal cancer is a genetically heterogeneous and complicated disease.     

Immunization with truncated recombinant protein SpaC of Erysipelothrix rhusiopathiae strain 715 serovar 18 confers protective immunity against challenge with various serovars

Previously, we showed that surface protective antigen (Spa) proteins of Erysipelothrix rhusiopathiae can be classified into three molecular species-SpaA, SpaB, and SpaC-and that SpaC is the most broadly cross-protective antigen among the three Spa proteins. In this study, we examined the ability of the α-helical domain, which comprises the N-terminal half of SpaC, to elicit cross-protective immunity in mice and pigs. Mice actively immunized with the full-length protein (rSpaC664) or the α-helical domain (rSpaC427), but not the C-terminal domain (rSpaC253), were protected against challenge with E. rhusiopathiae serovars 1a, 2, 6, 19, and 18 expressing heterologous (SpaA or SpaB) and homologous (SpaC) Spas. The α-helical domain seemed to provide better protection than rSpaC664, although the differences did not reach statistical significance. Similarly, mice passively immunized with rabbit anti-rSpaC664 or anti-rSpaC427 sera, but not anti-rSpaC253 serum, were protected from challenge with various serovars. Pigs immunized with SpaC427 also developed specific antibodies against Spa proteins and were protected from challenge with the highly virulent heterologous E. rhusiopathiae strain Fujisawa (serovar 1a). Taken together, these results demonstrate for the first time the striking protective efficacy of the α-helical domain-mediated immunization in both mice and pigs, thereby highlighting its utility as the most promising candidate for the development of a safe and effective vaccine against erysipelas.     

Antitumor effect of OK-432-derived DNA: one of the active constituents of OK-432, a streptococcal immunotherapeutic agent

OK-432 is a Streptococcus-derived immunotherapeutic agent for malignancies. Our group has tried to identify the effective components of OK-432 and has succeeded in isolating a lipoteichoic acid-related preparation designated as OK-PSA, which is a strong inducer of T helper 1 (T(H)1) cells, and elicits an anticancer effect via Toll-like receptor (TLR) 4. Conversely, bacterial DNA with unmethylated CpG motifs can stimulate a T(H)1-type host response via TLR9. The unmethylated CpG DNA contained in OK-432 may play a role in its anticancer effect. In the current study, we investigated the effect of OK-432-derived DNA (OK-DNA) in augmenting the anticancer immune response. Analysis of OK-DNA with the restriction enzymes Hpa II and MspI revealed that OK-DNA contained unmethylated CpG motifs. OK-DNA induced TH1-type cytokines such as interferon-gamma, tumor necrosis factor-alpha, interleukin (IL)-12, and IL-18 and augmented killer cell activities in vitro on human peripheral blood mononuclear cells, whereas the methylated OK-DNA did not. Cytokines were also produced by OK-DNA-stimulated splenocytes derived from wild-type mice but not from TLR9-deficient mice. In the in vivo study, peritumoral administration of OK-DNA resulted in a significant inhibition of tumor growth in syngeneic tumor-bearing wild-type and TLR4-deficient mice but not in TLR9-deficient mice. The antitumor effect of OK-432 in TLR9-deficient mice was significantly but partially reduced compared with that in wild-type mice, whereas the effect of OK-432 was almost completely eliminated in TLR4-deficient mice. These findings suggest that unmethylated CpG DNA in OK-432 functions as an active component in OK-432-induced anticancer immunity via TLR9.     

The efficacy of safety winged steel needles on needlestick injuries

Safety winged steel needles were introduced at the University of Tokyo Hospital in January 2001. We studied their effect in needlestick injuries. A total of 952 'needlestick and sharp-object injuries were reported. From January 1999 to December 2004, Cases of injury with winged steel needles decreased dramatically soon after safety devices were introduced, from 19.8% in Apr.-Dec.2000 to 6.7% in 2001 and 5.5% in 2002 (p < .01). They began to increase, however, in July 2002, decreased again after medical staff members mere given lectures and notices by e-mail. Due to the introduction of safety devices, cases classified as a "while recapping a used needle" and "when puncturing rubber stoppers" decreased. Among 17 injuries with safety winged steel needles, the most common cases were "safety mechanism not activated". We estimated that 76.5% of cases with safety winged steel needles could be prevented if they were used properly. In conclusion, the introduction of safety winged steel needles effectively reduced cases of injury with such needles. It is thus important to regularly remind hospital staff of safety device techniques and information reduce the such injuries.     

Molecular identification and phylogenetic relationships of trichomonad isolates of galliform birds inferred from nuclear small subunit rRNA gene sequences

Histomonas meleagridis is the etiological agent of histomonosis or blackhead disease. Recently, genotyping, based on polymerase chain reaction and sequencing of internal transcribed spacer-1 sequences was applied to various isolates originating from fowl. Three genotypes were described: types I and II isolates were associated with clinical disease and probably derived from H. meleagridis, whereas, type III isolates were not disease-associated and likely corresponded to Parahistomonas wenrichi according to morphological observations. However, this latter species has never been characterized at the molecular level and its phylogenetic relationships with other parabasalids remained hypothetical. To confirm the identification of these isolates, small subunit rRNA gene sequences were obtained from representatives of types I, II, and III and analyzed in a broad phylogeny including 64 other parabasalid sequences. From our phylogenetic trees, we confirmed that types I and II isolates were closely related, if not identical, to H. meleagridis, while type III isolates represented P. wenrichi. Both species clustered together with high support. This grouping suggested that speciation leading to these two species inhabiting the same hosts and ecological niche occurred recently in birds. In addition, speciation was likely followed by loss of pathogenicity in P. wenrichi.     

Plasma concentrations of VCAM‐1 and PAI‐1: A predictive biomarker for post‐operative recurrence in colorectal cancer

This prospective study used antibody suspension bead arrays to identify biomarkers capable of predicting post‐operative recurrence with distal metastasis in patients with colorectal cancer. One hundred colorectal cancer patients who underwent surgery were enrolled in this study. The median follow‐up period was 3.9 years. The pre‐operative plasma concentrations of 24 angiogenesis‐related molecules were analyzed with regard to the TNM stage and the development of post‐operative recurrence. The concentrations of half of the examined molecules (13/24) increased significantly according to the TNM stage (P < 0.05). Meanwhile, a multivariate logistic regression analysis revealed that the concentrations of vascular cell adhesion molecule 1 (VCAM‐1) and plasminogen activator inhibitor‐1 (PAI‐1) were significantly higher in the post‐operative recurrence group. The VCAM‐1 and PAI‐1 model discriminated post‐operative recurrence with an area under the curve of 0.82, a sensitivity of 0.75, and a specificity of 0.73. A leave‐one‐out cross‐validation was applied to the model to assess the prediction performance, and the result indicated that the cross‐validated error rate was 12.5% (12/96). In conclusion, our results demonstrate that antibody suspension bead arrays are a powerful tool to screen biomarkers in the clinical setting, and the plasma levels of VCAM‐1 and PAI‐1 together may be a promising biomarker for predicting post‐operative recurrence in patients with colorectal cancer. (Cancer Sci 2010)     

Aristolochic acid‐induced upper tract urothelial carcinoma in Taiwan: Clinical characteristics and outcomes

Aristolochic acid (AA), a component of all Aristolochia‐based herbal medicines, is a potent nephrotoxin and human carcinogen associated with upper urinary tract urothelial carcinoma (UUC). To investigate the clinical and pathological characteristics of AA‐induced UUC, this study included 152 UUC patients, 93 of whom had been exposed to AA based on the presence of aristolactam‐DNA adducts in the renal cortex. Gene sequencing was used to identify tumors with A:T‐to‐T:A transversions in TP53, a mutational signature associated with AA. Cases with both aristolactam‐DNA adducts and A:T‐to‐T:A transversions in TP53 were defined as AA‐UUC, whereas patients lacking both of these biomarkers were classified as non‐AA‐UUC. Cases with either biomarker were classified as possible‐AA‐UUC. Forty (26%), 60 (40%), and 52 (34%) patients were classified as AA‐UUC, possible‐AA‐UUC and non‐AA‐UUC, respectively. AA‐UUC patients were younger (median ages: 64, 68, 68 years, respectively; p=0.189), predominately female (65%, 42%, 35%, respectively; p=0.011), had more end‐stage renal disease (28%, 10%, 12%, respectively; p=0.055), and were infrequent smokers (5%, 22%, 33%, respectively; p=0.07) compared to possible‐AA‐UUC and non‐AA‐UUC patients. All 14 patients who developed contralateral UUC had aristolactam‐DNA adducts; ten of these also had signature mutations. The contralateral UUC‐free survival period was shorter in AA‐UUC compared to possible‐ or non‐AA‐UUC (p=0.019 and 0.002, respectively), whereas no differences among groups were observed for bladder cancer recurrence. In conclusion, AA‐UUC patients tend to be younger and female, and have more advanced renal disease. Notably, AA exposure was associated with an increased risk for developing synchronous bilateral and metachronous contralateral UUC.