A maternal high-fat diet may accelerate adipo-immunologic aging in offspring.

AIM: Maternal obesity and improper nutrition predispose offspring to chronic metabolic diseases. Although the frequency of these diseases increases with aging, the effect of a maternal high-fat diet on aged offspring remains elusive. MAIN METHODS: C57BL/6J female mice were fed a high-fat (HF) diet or a control (CON) diet and then mated. All offspring remained with their birth dam until weaning at 3 weeks. After weaning, the offspring from the HF and CON diet-fed dams were given either the HF diet or CON diet, which resulted in four groups: CON/CON, CON/HF, HF/CON, and HF/HF. All mice were immunized with ovalbumin and then sacrificed at 70 weeks. KEY FINDINGS: The body weights in offspring from dam exposed to a HF diet were significantly higher than those in offspring from dam fed a CON diet in the early stage of life but then became lower in the later stage of life. The serum adiponectin levels were lower in offspring from dam exposed to a HF diet and were correlated with adiposity measured by visceral and subcutaneous fat mass. Non-alcoholic fatty liver disease was much more severe in the livers of offspring from the maternal HF groups. In particular, lobular inflammation and fibrosis were prominent in the HF/HF group. Regarding immunological parameters, senescence-associated T cells were increased, and natural killer T cells were decreased by the effect of both maternal and offspring HF diet. SIGNIFICANCE: We have demonstrated that a maternal high-fat diet may accelerate the adipo-immunologic aging process.

Effects of chocolate containing Leuconostoc mesenteroides strain NTM048 on immune function: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Previous reports showed that oral administration of Leuconostoc mesenteroides strain NTM048 increases IgA levels and CD4+ T cell population in feces and mice, respectively, as revealed by flow cytometric analysis of splenocytes. This study aimed to evaluate the effect of chocolate supplemented with L. mesenteroides strain NTM048 (> 1.00 × 109 CFU/day, NTM048) on the immune parameters of healthy subjects, using a randomized, placebo-controlled, double-blinded study design. METHODS: Participants (mean age: 46.3 years) ingested 28 g of test food daily, at a time of their own choice, for 4 weeks. The immunological parameters of all participants were evaluated two times (pre- and post- ingestion). At the end of the study, various immunological parameters of the participants were measured and scoring of immunological vigor (SIV) was performed using a comprehensive algorithm. RESULTS: Ingestion of NTM048-supplemented chocolate significantly improved SIV in the NTM048 group (18.6 ± 1.6) compared to that in the placebo group (17.8 ± 2.0) after 4 weeks (p = 0.049). Several immunological parameters (CD8+T cells, CD8+CD28+ T cells, and memory T cells) were significantly elevated in the NTM048 group as compared to the placebo group (all p < 0.05). In addition, T cell proliferation index at post-ingestion significantly increased compared with that at pre-ingestion in the NTM048 (p = 0.017) and placebo groups (p = 0.037), although no differences were observed between the two groups. CONCLUSION: Our results suggest that ingestion of chocolate supplemented with NTM048 is effective against the age-related decline in T cell-related immune functions. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000021989. Registered 19 April 2016, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000025321.

Effects of in vitro heat shock on immune cells in diet-induced obese mice.

Obesity has been associated with impaired immune responses and inflammation. The mechanisms underlying these immune disturbances in obesity are not yet clarified. This study investigated the effects of in vitro heat shock (HS) on immune cells from the point of view of thymocyte apoptosis and T-cell mitogen-stimulated splenocyte cytokine production as well as the heat shock protein 70 (HSP70) protein levels in diet-induced obese mice to explore a possible association between the disturbance of T cell immunity and HS response in obesity. Obese mice had increased apoptotic and necrotic thymocytes populations and increased splenocyte cytokine production of both proinflammatory and anti-inflammatory cytokines compared with lean mice. The in vitro HS at 42°C decreased the rate of live cells in thymocytes, and the degree of the decrease was larger in obese mice compared with lean mice. The in vitro HS increased the intracellular and extracellular HSP70 protein levels in thymocytes and splenocytes, while the effects of obesity on the HSP70 protein levels were not obvious. The in vitro HS prior to T cell mitogen stimulation decreased IFN-γ and IL-10 production by mitogen-stimulated splenocytes. This change in cytokine production due to HS was not affected by obesity. The obvious alteration of the HSP70 protein levels and association between cytokine production and the HS response in obesity were not found in this obesity model; however, our results indicate an association between the viability of thymocytes and an altered HS response in obesity and provide evidence that the increase in thymocyte apoptosis and acceleration of thymus involution in obesity could be, in part, due to the alteration of the HS response.

Immunomodulation in Middle-Aged Humans Via the Ingestion of Physta® Standardized Root Water Extract of Eurycoma longifolia Jack--A Randomized, Double-Blind, Placebo-Controlled, Parallel Study.

This study was aimed to investigate the capacity of a standardized root water extract of Eurycoma longifolia (Tongkat Ali, TA), Physta® to modulate human immunity in a middle-aged Japanese population. This randomized, double-blind, placebo-controlled, parallel study was conducted for 4 weeks. Eighty-four of 126 subjects had relatively lower scores according to Scoring of Immunological Vigor (SIV) screening. Subjects were instructed to ingest either 200 mg/day of TA or rice powder as a placebo for 4 weeks [TA and Placebo (P) groups] and to visit a clinic in Tokyo twice (weeks 0 and 4). SIV, immunological grade, immunological age, and other immune parameters were measured. Eighty-three subjects completed the study; 40 in the TA group and 41 in the P group were statistically analyzed, whereas two were excluded from the analyses. At week 4, the SIV and immunological grade were significantly higher in the TA group than those in P group (p < 0.05). The numbers of total, naïve, and CD4(+) T cells were also higher in the TA group than those in P group (p < 0.05). No severe adverse events were observed. The results suggest that ingestion of the root water extract of TA (Physta®) enhances comprehensive immunity in both middle-aged men and women. This study is registered in UMIN-CTR (UMIN000011753).

Trade off situation between thymus and growth hormone: age-related decline of growth hormone is a cause of thymic involution but favorable for elongation of lifespan.

High level of growth hormone (GH) is necessary for the activation of thymic function to promote T cell differentiation in the early stage of animal life. In the later stage of the life, administration of GH promotes the development of immune system and rejuvenates declined immune function of elderly people. By contraries, GH deficiency is favorable for the longer lifespan, as hypo-pituitary dwarf mice such as Ames and Snell dwarf mice exhibit longer lifespan than control. Furthermore over-expression of heterologous or homologous GH in transgenic mice shortens the lifespan. Ecuadorians carrying mutations of GH receptor gene are short in height, but exhibited low frequency of malignancy and no cases of diabetes. These data indicate that GH is necessary for the development of thymus dependent immune system but GH deficiency is favorable for long life span and decreases occurrence of cancer and DM. This situation is a kind of trade off situation between the immune system and GH. Thus the early decline of high level of GH occurring shortly after the birth is a cause of early decline of thymic functions, but favorable for longer lifespan. This situation could be a kind of trade off situation between thymus and GH.

Improvement in Human Immune Function with Changes in Intestinal Microbiota by Salacia reticulata Extract Ingestion: A Randomized Placebo-Controlled Trial.

UNLABELLED: Plants belonging to the genus Salacia in the Hippocrateaceae family are known to inhibit sugar absorption. In a previous study, administration of Salacia reticulata extract in rats altered the intestinal microbiota and increased expression of immune-relevant genes in small intestinal epithelial cells. This study aimed to investigate the effect of S. reticulata extract in human subjects by examining the gene expression profiles of blood cells, immunological indices, and intestinal microbiota. The results revealed an improvement in T-cell proliferation activity and some other immunological indices. In addition, the intestinal microbiota changed, with an increase in Bifidobacterium and a decrease in Clostridium bacteria. The expression levels of many immune-relevant genes were altered in blood cells. We concluded that S. reticulata extract ingestion in humans improved immune functions and changed the intestinal microbiota. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000011732.

Slower immune system aging in women versus men in the Japanese population.

BACKGROUND: Gender-related differences in humans are commonly observed in behaviour, physical activity, disease, and lifespan. However, the notion that age-related changes in the immune system differ between men and women remains controversial. To elucidate the relationship between immunological changes and lifespan, peripheral blood mononuclear cells from healthy Japanese subjects (age range: 20-90 years; N = 356) were analysed by using three-colour flow cytometry. The proliferative activities and cytokine-producing capacities of T cells in response to anti-CD3 monoclonal antibody stimulation were also assessed. RESULTS: An age-related decline in the number of T cells, certain subpopulations of T cells (including CD8+ T cells, CD4+CDRA+ T cells, and CD8+CD28+ T cells), and B cells, and in the proliferative capacity of T cells was noted. The rate of decline in these immunological parameters, except for the number of CD8+ T cells, was greater in men than in women (p < 0.05). We observed an age-related increase or increasing trend in the number of CD4+ T cells, CD4+CDRO+ T cells, and natural killer (CD56+CD16+) cells, as well as in the CD4+ T cell/CD8+ T cell ratio. The rate of increase of these immunological parameters was greater in women than in men (p < 0.05). T cell proliferation index (TCPI) was calculated from the T cell proliferative activity and the number of T cells; it showed an age-related decline that was greater in men than in women (p < 0.05). T cell immune score, which was calculated using 5 T cell parameters, also showed an age-related decline that was greater in men than in women (p < 0.05). Moreover, a trend of age-related decreases was observed in IFNγ, IL-2, IL-6, and IL-10 production, when lymphocytes were cultured with anti-CD3 monoclonal antibody stimulation. The rate of decline in IL-6 and IL-10 production was greater in men than in women (p < 0.05). CONCLUSION: Age-related changes in various immunological parameters differ between men and women. Our findings indicate that the slower rate of decline in these immunological parameters in women than that in men is consistent with the fact that women live longer than do men.

Analysis of adipose tissues and stromal vascular cells in a murine arthritis model.

PURPOSE: Changes in body composition in rheumatoid arthritis (RA), including a reduction in skeletal muscle mass and the accumulation of visceral fat, have been identified, and the interaction between immune abnormality and metabolic disorders has received much attention. The effect of a high-fat (HF) diet and the role of adipose tissue in an arthritis model were investigated. METHODS: The effect of an HF diet on the histopathology of joints in murine type II collagen-induced arthritis (CIA) was evaluated. The morphology and adipokine production of adipose tissues were analyzed, and macrophages in the stromal vascular fraction (SVF) were counted by flow cytometry. Serum adipokine levels were measured by ELISA. RESULTS: Significant exacerbation of joint destruction and aggravated pathological conditions were observed in CIA mice that were fed an HF diet. However, the boundary length of adipose tissue tended to decrease and the levels of adipokines (leptin and adiponectin) were lowered by the induction of arthritis. In HF/CIA mice, nevertheless, the production of MCP-1 in adipose tissues and the accumulation of macrophages in the SVF were significantly higher than CON/CIA group. The serum leptin/adiponectin (L/A) ratio was positively correlated with the number of macrophages in the SVF and MCP-1 production by adipose tissue, particularly in the CIA group. CONCLUSION: Functional alterations of adipose tissues could be originated from HF diet during developing arthritis. An abnormal activation of macrophages and an increased production of MCP-1 in adipose tissues might be both involved in joint destruction and inflammation.

Recreational music-making modulates immunological responses and mood states in older adults.

Given that previous studies have shown that recreational music-making has benefits for younger individuals, we explored two questions. (1) Could a recreational music-making protocol improve mood and modulate immunological responses in a direction opposite to that associated with chronic stress in older adults? (2) Would the protocol affect older and younger participants differently? Two groups of volunteers demarcated at age 65 years underwent identical one-hour recreational music-making interventions. Pre-and post-intervention data were collected using blood samples and mood state questionnaires. Data from 27 older and 27 younger volunteers were analyzed for cytokine production levels, natural killer cell activity, plasma catecholamines, and numbers of T cells, T cell subsets, B cells, and natural killer cells. Exercise expenditure was also recorded. In the older group, we found significant increases in the number of lymphocytes, T cells, CD4+ T cells, memory T cells, and production of interferon-gamma and interleukin-6. In the younger group, modulation was non-significant. Worthy of note was the specific immunological changes in the direction opposite to that expected with chronic stress in the older group. The increase in Th1 cytokine IFN-gamma and unchanged Th2 cytokine IL-4 and IL-10 levels in the older group suggests a shift to a Th1-dominant status, a shift opposite to that expected with stress. However, the immunological changes were not statistically different between the two groups. Mood states improved in both groups, but were also not statistically different between groups. Although no statistically significant difference was found between the two age groups, the improvement in immunological profile and mood states in the older group and the low level of energy required for participation suggest this music-making protocol has potential as a health improvement strategy for older individuals.

Decline of T cell-related immune functions in cancer patients and an attempt to restore them through infusion of activated autologous T cells.

We developed a scoring system that can combine several immunological parameters and express the immune status of individuals as a simple numeral. T cell immune score was obtained by using 5T cell-related parameters: number of T cells, ratio of CD4(+)T cells to CD8(+)T cells, number of naïve T cells, ratio of naïve T cells to memory T cells, and T cell proliferative index (TCPI). TCPI was calculated by using number of T cells and their proliferative activity. We assessed T cell immune score in 103 patients with colorectal cancer and 51 healthy age-matched controls. The results were as follows: (1) T cell-immune score of patients in stages I-IV before surgery was significantly decreased as compared with controls. (2) The number of regulatory T cells in patients in stages I-IV gradually increased with disease progression. (3) T cell immune score was strongly suppressed after surgery, but were recovered to the initial level within a month. (4) Furthermore, restoration of immunological function was attempted in cancer patients by infusion of activated autologous T cells. The effectiveness was confirmed by an increase of TCPI in many cancer patients.

Recreational music-making modulates natural killer cell activity, cytokines, and mood states in corporate employees.

BACKGROUND: With growing evidence linking job stress to illness, finding an effective means of stress management has become a challenging international endeavor. Although music therapy has attracted the attention of various fields as a promising method for alleviating stress, lack of standardization and paucity of data have served as impediments to widespread utilization. MATERIAL/METHODS: The effects of a Recreational Music-Making (RMM) group drumming protocol was evaluated on Japanese male corporate employees. A total of 20 volunteers participated in a one-hour RMM session while 20 volunteers engaged in leisurely reading for one hour (controls). After a six-month interval, the groups switched activities and underwent one session each. Pre- and post-intervention data were collected using mood state questionnaires and blood samples. Individual and group mean values for natural killer (NK) cell activity, NK cell percentage, and cytokine gene expression were analyzed. RESULTS: NK cell activity in the RMM group increased among individuals with low pre-intervention levels, and decreased among those with high pre-intervention levels. A significant correlation was established between changes in NK cell activity and the changes in the level of gene expressions for interferon-gamma and interleukin-10. The RMM group demonstrated enhanced mood, lower gene expression levels of the stress-induced cytokine interleukin-10, and higher NK cell activity when compared to the control. CONCLUSIONS: Based upon documented changes in NK cell activity, coupled with gene expression changes for interferon-gamma, interleukin-10, and improved mood, this RMM protocol has significant potential for utilization in the corporate wellness environment.

Prostaglandin D2 plays an essential role in chronic allergic inflammation of the skin via CRTH2 receptor.

PGD(2) plays roles in allergic inflammation via specific receptors, the PGD receptor designated DP and CRTH2 (chemoattractant receptor homologous molecule expressed on Th2 cells). We generated mutant mice carrying a targeted disruption of the CRTH2 gene to investigate the functional roles of CRTH2 in cutaneous inflammatory responses. CRTH2-deficent mice were fertile and grew normally. Ear-swelling responses induced by hapten-specific IgE were less pronounced in mutant mice, giving 35-55% of the responses of normal mice. Similar results were seen in mice treated with a hemopoietic PGD synthase inhibitor, HQL-79, or a CRTH2 antagonist, ramatroban. The reduction in cutaneous responses was associated with decreased infiltration of lymphocytes, eosinophils, and basophils and decreased production of macrophage-derived chemokine and RANTES at inflammatory sites. In models of chronic contact hypersensitivity induced by repeated hapten application, CRTH2 deficiency resulted in a reduction by approximately half of skin responses and low levels (63% of control) of serum IgE production, although in vivo migration of Langerhans cells and dendritic cells to regional lymph nodes was not impaired in CRTH2-deficient mice. In contrast, delayed-type hypersensitivity to SRBC and irritation dermatitis in mutant mice were the same as in wild-type mice. These findings indicate that the PGD(2)-CRTH2 system plays a significant role in chronic allergic skin inflammation. CRTH2 may represent a novel therapeutic target for treatment of human allergic disorders, including atopic dermatitis.

Importance of gastrointestinal ingestion and macromolecular antigens in the vein for oral tolerance induction.

Oral administration of a certain dose of antigen can generally induce immunological tolerance against the same antigen. In this study, we showed the temporal appearance of ovalbumin (OVA) antigens in both portal and peripheral blood of mice after the oral administration of OVA. Furthermore, we detected 45,000 MW OVA in mouse serum 30 min after the oral administration of OVA. Based on this observation, we examined whether the injection of intact OVA into the portal or peripheral vein induces immunological tolerance against OVA. We found that the intravenous injection of intact OVA did not induce immunological tolerance but rather enhanced OVA-specific antibody production in some subclasses, suggesting that OVA antigens via the gastrointestinal tract but not intact OVA may contribute to establish immunological tolerance against OVA. Therefore, we examined the effects of digesting intact OVA in the gastrointestinal tract on the induction of oral tolerance. When mice were orally administered or injected into various gastrointestinal organs, such as the stomach, duodenum, ileum, or colon and boosted with intact OVA, OVA-specific antibody production and delayed-type hypersensitivity (DTH) response were significantly enhanced in mice injected into the ileum or colon, compared with orally administered mice. These results suggest that although macromolecular OVA antigens are detected after oral administration of OVA in tolerant-mouse serum, injection of intact OVA cannot contribute to tolerance induction. Therefore, some modification of macromolecular OVA in the gastrointestinal tract and ingestion may be essential for oral tolerance induction.

Cancer and aging: symposium of the 27th annual meeting of the Japanese society for biomedical gerontology, Tokyo.

Although many hypotheses have been proposed to explain the strong link between aging and cancer, the exact mechanisms responsible for the increased frequency of occurrence of cancer with advancing age have not been fully defined. Recent evidence indicates that malregulation of the apoptotic process may be involved in some aging process as well as in the development of cancer. Although it is still under debate how apoptosis is expressed during aging in vivo, this phenomenon is an important factor in unwinding the complicated mechanisms that link cancer and aging. In this review, we report on the discussion at the symposium of the 27th annual meeting of the Japanese society for biomedical gerontology, regarding recent findings from aging and carcinogenesis studies using animal models, the characteristics of cancer in patients with Werner's syndrome, the epigenetic changes in human cancers and aging, and the characteristics of human cancers in the elderly. It was concluded that apoptosis plays a role in the aging process and carcinogenesis in vivo, likely as an inherent protective mechanism against various kinds of damages to genes/chromosomes.

Expression level of Wnt signaling components possibly influences the biological behavior of colorectal cancer in different age groups.

Advancing of age apparently influences the behavior of colorectal cancer (CRC). The pattern of activation and expression of Wnt target genes may influence the behavior of the cancer. In the present study, the level of activation of some elements of Wnt signaling was evaluated and correlated with the patient's age and clinicopathological characteristics of the tumor. Beta-catenin and c-Myc mRNA expressions were evaluated by semiquantitative real-time PCR, and subcellular localization of the beta-catenin protein was evaluated by immunohistochemistry. Patients aged 70-84 tended to have locally advanced disease more frequently than younger patients. The same group of patients also more frequently had high nuclear expression of beta-catenin protein and higher expression of c-Myc mRNA. Beta-catenin mRNA had a rather constant expression with advancing of age. High nuclear expression of beta-catenin and high expression of c-Myc were apparently also correlated with locally advanced disease. We concluded that the level of Wnt signaling activation might influence the behavior of the disease in different age groups.

Identification of a novel isoform of ZAP-70, truncated ZAP kinase.

We identified a novel cDNA encoding truncated ZAP-70, which lacked the SH2 domain and a part of interdomain B, and named it truncated ZAP kinase (TZK). TZK was expressed in the thymus, spleen, and lymph nodes with ZAP-70. TZK was expressed in CD44+CD25- thymocytes up to mature T cells, but ZAP-70 was not expressed in CD44+CD25- or CD44+CD25+ thymocytes. ZAP-70 or TZK was transfected into P116 cells derived from a Jurkat T-cell line deficient in ZAP-70. The P116 cells with ZAP-70 induced the T-cell receptor-mediated signal transduction, but the cells expressing TZK did not. While ZAP-70 was accumulated at the immune synapse, TZK was not. Meanwhile, impaired phosphorylation of SLP-76, one of the substrates of ZAP-70, in P116 cells upon pervanadate stimulation was rescued in the cells expressing TZK. These findings show that TZK is a novel isoform of ZAP-70, which is expressed in pre-T-cell receptor-minus thymocytes and functions as a kinase not associated with T-cell receptor.

Regulation of osteoclastogenesis by three human RANKL isoforms expressed in NIH3T3 cells.

Receptor activator of nuclear factor-kappaB ligand (RANKL) induces osteoclastogenesis by binding with the receptor, receptor activator of nuclear factor-kappaB in the presence of macrophage colony-stimulating factor. Three human RANKL isoforms, hRANKL1, hRANKL2, and hRANKL3, were identified. hRANKL1 was identical to previously reported RANKL and possessed intracellular, transmembrane, and extracellular domains, hRANKL2 did not have the intracellular domain, and hRANKL3 did not have the intracellular and transmembrane domains. When bone marrow macrophages were cultured with NIH3T3 cells expressing hRANKL1, osteoclasts were formed, but when cultured with NIH3T3 cells expressing hRANKL2 or hRANKL3, no tartrate resistant acid phosphatase-positive cell was observed. In the coculture system, coexpression of hRANKL3 with hRANKL1 significantly inhibited the formation of osteoclasts by hRANKL1, but coexpression of hRANKL2 with hRANKL1 did not affect the osteoclastogenesis by hRANKL1 significantly. These results suggest that the activity of osteoclastogenesis by hRANKL1 is regulated by the attenuator, hRANKL3.

Multimerization of the receptor activator of nuclear factor-kappaB ligand (RANKL) isoforms and regulation of osteoclastogenesis.

The receptor activator of nuclear factor-kappaB ligand (RANKL), a member of the tumor necrosis factor family, is a transmembrane protein, which is known as an essential initiation factor of osteoclastogenesis. Previously, we identified three RANKL isoforms. RANKL1 was identical to the originally reported RANKL. RANKL2 had a shorter intracellular domain. RANKL3 did not have the intracellular or transmembrane domains and was suggested to act as a soluble form protein. Here, we show that RANKL forms homo- or heteromultimers. NIH3T3 cells transfected with RANKL1 or RANKL2 form mononuclear tartrate-resistant acid phosphatase-positive preosteoclasts in an in vitro osteoclastogenesis assay system. Coexpression of RANKL1 and RANKL2 induces multinucleated osteoclasts. RANKL3 has no effect on the formation of preosteoclasts or osteoclasts but significantly inhibits fusion of preosteoclasts when coexpressed with RANKL1 and RANKL2. These findings imply the presence of multiple multimeric structures of RANKL, which may regulate bone metabolism.

Radiation-induced-thymic lymphoma occurs in young, but not in old mice.

Young mice exposed to fractionated whole-body irradiation develop thymic lymphoma. By using young and old mice, we examined the effect of age on the occurrence of radiation-induced thymic lymphoma in mice. In the first experiment, young and old mice were grafted with newborn thymus under kidney capsule and then treated with fractionated whole-body irradiation (FWI). In the second and third experiments, four combinations of bone marrow chimeras were constructed by transplanting bone marrow cells from young and old mice into young and old mice. Then these chimera mice were grafted with newborn thymus and treated with fractionated whole-body irradiation. The results in the present study indicate that the incidence of thymic lymphoma is influenced by age factors of thymic microenvironment, bone marrow, and host environment. If they are all young, the incidence of thymic lymphoma is high. If one of these is old, the incidence definitely decreases. Thymic lymphoma never occurred in old thymic environment even in the presence of young thymocytes. In conclusion, age advantage is present in the induction of thymic lymphoma after the treatment with FWI and the incidence definitely decreases in the presence of old factors.

Poor prognosis of colorectal cancer in patients over 80 years old is associated with down-regulation of tumor suppressor genes.

UNLABELLED: GOALS, BACKGROUND: The elderly population has been increasing during the last half a century and it would be important to know how aging influences the occurrence and biologic behavior of cancers. STUDY: We investigated clinicopathologic characteristics of colorectal cancer in 1354 patients who underwent colorectal cancer resection and compared the results between extremely elderly patients (over 80 years old) and middle-aged/elderly patients (40 to less than 80 years old). Furthermore, we also examined expression of tumor suppressor genes and Cox-2 using frozen samples of colorectal cancer obtained from 62 patients ranging in age from 45 to 87 years. RESULTS: The results obtained in the extremely aged patients were: (1) higher ratio of women, (2) higher incidence at the proximal site, (3) higher incidence of cases with deeper invasion, (4) higher incidence of cases with lymph node metastasis (5) poorer survival rate as compared with middle-aged/elderly patients, and (6) lower mRNA expression levels of p27 and p53. CONCLUSIONS: These findings taken together suggest that poor prognosis of colorectal cancer in patients over 80 years is associated with down-regulation of mRNA expression of some tumor suppressor genes.