Milk and dairy products in cancer prevention: focus on bovine lactoferrin

Milk and dairy products constitute an important part of the western style diet. A large number of epidemiological studies have been conducted to determine effects of consumption on cancer development but the data are largely equivocal, presumably reflecting the different included components. It has been proposed that whereas fats in general could promote tumor development, individual milk fats like conjugated linoleic acid could exert inhibitory effects. There is also considerable evidence that calcium in milk products protects against colon cancer, while promoting in the prostate through suppression of circulating levels of 1,25-dihydroxyvitamin D3. Whey protein may also be beneficial, as shown by both animal and human studies, and experimental data have demonstrated that the major component bovine lactoferrin (bLF), inhibits colon carcinogenesis in the post-initiation stage in male F344 rats treated with azoxymethane (AOM) without any overt toxicity. The incidence of adenocarcinomas in the groups receiving 2% and 0.2% bLF were thus 15% and 25%, respectively, in contrast to the 57.5% control value (P<0.01 and P<0.05, respectively). Results in other animal models have provided further indications that bLF might find application as a natural ingredient of milk with potential for chemoprevention of colon and other cancers.     

Identification of 4-Trimethylaminobutyraldehyde Dehydrogenase (TMABA-DH) as a Candidate Serum Autoantibody Target for Kawasaki Disease

Kawasaki disease (KD), an acute vasculitis that preferentially affects coronary arteries, is still the leading cause of acquired heart disease in children. Although the involvement of immune system malfunction in the onset of KD is suggested, its etiology still remains to be clarified. We investigated autoantibodies in KD patients, which are frequently found in sera from patients with autoimmune diseases, vasculitides and arteritides. We performed two-dimensional western blotting and LC-MS/MS to analyze the antigens of autoantibodies, detected two protein spots with 4 out of 24 sera from KD patients but not with 6 control sera, and identified the antigens as 4-trimethylaminobutyraldehyde dehydrogenase (TMABA-DH). A slot blot analysis with TMABA-DH as an antigen also revealed higher reactivities of patients'' sera than control sera (positive rates: 18/43 vs 3/41). Using an enzyme-linked immunosorbent assay (ELISA), we found that the reactivity of anti-TMABA-DH antibodies in sera from KD patients was significantly higher than that in sera from age-matched controls. The optimal cut-off value of 0.043 had a sensitivity of 83.7% and a specificity of 80.0% in detecting KD patients (positive rates: 37/43 for KD patients, 9/41 for controls). Immunohistochemistry performed on thin sections of rat heart revealed that TMABA-DH colocalized with myosin light chains in cardiac myocytes. Patient sera with high reactivity gave similar immunostaining pattern. These results suggest that the detection of anti-TMABA-DH autoantibody could be a potential strategy for a diagnosis of KD.     

Clinical Features and Treatment Modes of Mandibular Fracture at the Department of Oral and Maxillofacial Surgery,Shimane University Hospital,Japan

Background

The number of elderly patients with maxillofacial trauma is rapidly increasing due to active lifestyles and longevity. Shimane prefecture has the fastest growing proportion of elderly individuals in Japan. The aim of this study was to reveal the distinctive features and treatment modes of mandibular fracture treatment mode in patients requiring hospitalization at the Department of Oral and Maxillofacial Surgery, Shimane University Hospital, Japan.

Patients and Methods

Patient age, sex, period between injury and first consultation, years since injury, cause of injury, fracture site, treatment, and duration of hospitalization were evaluated. Univariate Poisson regression, relative risk with 95% confidence interval based on the Wald test, Fisher’s exact test, and Kruskal-Wallis test were used to explore associations among clinical and demographic variables.

Results

In total, 305 patients were diagnosed with and hospitalized for mandibular fracture from 1980 to 2010. Younger age increased the risk for mandibular fracture. Incidence was higher in males than females, particularly in the young, but the male to female ratio decreased with age. The period until first hospital consultation decreased progressively over the study period. Fall was a much more frequent cause in patients aged ≥60 than in those aged <60 years. Mandibular fracture with condyle, symphysis, and angle involvement were most common and were associated with sex, age, and treatment mode. Length of hospitalization has decreased since 1980.

Conclusion

In our department, patients aged ≥60 years accounted for a greater proportion of mandibular fracture cases than in many previous studies, reflecting the greater proportion of elderly residents in Shimane prefecture.     

X radiation up-regulates the occurrence and the multiplicity of invasive carcinomas in the intestinal tract of Apc(min/+) mice

X rays are well known to cause genetic damage and to induce many types of carcinomas in humans. The Apc(min/+) mouse, an animal model for human familial adenomatous polyposis (FAP), contains a truncating mutation in the APC gene and spontaneously develops intestinal adenomas. To elucidate the role of X rays in the development of intestinal tumors, we examined the promotion of carcinogenesis in X-irradiated Apc(min/+) mice. Forty out of 77 (52%) X-irradiated Apc(min/+) mice developed adenocarcinomas that invaded the proprial muscle layer of the small intestine; 24 of 44 (55%) were in males, and 16 of 33 (49%) were in females. In contrast, invasive carcinomas were detected in the small intestines of only 13 of 64 (20%) nonirradiated Apc(min/+) mice; nine of 32 (28%) were in males and four of 32 (13%) were in females. These differences between X-irradiated and nonirradiated Apc(min/+) mice in the occurrence of invasive intestinal carcinomas were statistically significant (P < 0.05 for males, P < 0.005 for females). In wild-type mice, invasive carcinomas were not detected in either X-irradiated or nonirradiated mice. Apc(min/+) mice had many polyps in the large intestine with or without X irradiation; there was no difference in the number of polyps between the two groups. Also, invasive carcinomas were not detected in the large intestine with or without irradiation. The occurrence of mammary tumors, which was observed in Apc(min/+) mice, was found to be increased in irradiated Apc(min/+) mice (P < 0.01). Apc(min/+) mice had many polyps in the small and large intestines with or without X irradiation. X-irradiated Apc(min/+) mice had highly invasive carcinomas in the small intestine with multiplicities associated with invasiveness. Our results suggest that X radiation may promote the invasive activity of intestinal tumors in Apc(min/+) mice.     

High levels of human recombinant cyclooxygenase-1 expression in mammalian cells using a novel gene amplification method

We report the expression of a high level of human cyclooxygenase-1 (hCOX-1) in mammalian cells using a novel gene amplification method known as the IR/MAR gene amplification system. IR/MAR-plasmids contain a mammalian replication initiation region (IR) and a nuclear matrix attachment region (MAR) and amplify autonomously without a specific induction process. In this study, the IR/MAR-plasmid pΔBN.AR1 was cotransfected with pCAG-COX1, which expresses hCOX-1, into human HEK293T cells, and G418 and blasticidin S double-resistant cells were obtained in about 1month. Real-time PCR and Western blotting revealed that the expressions of hCOX-1 mRNA and protein in both polyclonal and monoclonal cells were remarkably higher than those in only pCAG-COX1-transfected control cells. Southern blotting demonstrated the amplification of the hCOX-1 gene, and the copy number of clone #43 obtained by the cotransfection of pΔBN.AR1 and pCAG-COX1 was more than 20 copies per cell, though that of clone #14 obtained without using the IR/MAR plasmid pΔBN.AR1 was only two copies. These results indicate that a high level of hCOX-1 expression was achieved as a result of hCOX-1 gene amplification. Furthermore, the crude extract from clone #43 showed a strong COX-1 activity, and the activity was inhibited by the representative COX-1 inhibitor indomethacin, with an IC(50) value of 36nM. These results demonstrate that the IR/MAR gene amplification system is a simple but useful method for generating highly productive mammalian cells.     

Tyrosine phosphorylation-dependent activation of TRPC6 regulated by PLC-γ1 and nephrin: effect of mutations associated with focal segmental glomerulosclerosis

Transient receptor potential canonicals (TRPCs) play important roles in the regulation of intracellular calcium concentration. Mutations in the TRPC6 gene are found in patients with focal segmental glomerulosclerosis (FSGS), a proteinuric disease characterized by dysregulated function of renal glomerular epithelial cells (podocytes). There is as yet no clear picture for the activation mechanism of TRPC6 at the molecular basis, however, and the association between its channel activity and pathogenesis remains unclear. We demonstrate here that tyrosine phosphorylation of TRPC6 induces a complex formation with phospholipase C (PLC)-γ1, which is prerequisite for TRPC6 surface expression. Furthermore, nephrin, an adhesion protein between the foot processes of podocytes, binds to phosphorylated TRPC6 via its cytoplasmic domain, competitively inhibiting TRPC6-PLC-γ1 complex formation, TRPC6 surface localization, and TRPC6 activation. Importantly, FSGS-associated mutations render the mutated TRPC6s insensitive to nephrin suppression, thereby promoting their surface expression and channel activation. These results delineate the mechanism of TRPC6 activation regulated by tyrosine phosphorylation, and imply the cell type-specific regulation, which correlates the FSGS mutations with deregulated TRPC6 channel activity.