Tsuyoshi Kataoka

Chemoprevention of N-Nitroso-N-methylurea-induced Rat Mammary Carcinogenesis by Soy Foods or Biochanin A

We examined the effects of soybeans, a soy product (miso) and biochanin A, an isoflavone derivative, on N‐nitroso‐N‐methylurea (MNU)‐induced rat mammary carcinogenesis. Seven‐week‐old female CD/Crj rats received a single i.v. dose (40 mg/kg body weight) of MNU. After administration of MNU, rats were fed diet containing 0% (control), 2% or 10% soybeans, or 10% miso as a soy‐supplemented diet, or 10 or 50 mg/kg biochanin A. All rats were observed for 18 weeks after MNU administration. At 18 weeks, the multiplicity (mean tumors/rat) of palpable mammary tumors was significantly decreased in the 10% soybean (1.1) and 10% miso (1.2) diet groups compared to the control (2.2) (P<0.05, respectively). In the biochanin A‐supplemented diet groups, the incidence (percentage of rats with tumors) was significantly decreased in the 50 mg/kg (32%) diet group compared to the control (80%) (P<0.01), and the multiplicity was significantly decreased in both the 10 mg/kg (0.7) and 50 mg/kg (0.5) diet groups compared to the control (2.2) (P<0.01 and P<0.001, respectively). The proliferative cell nuclear antigen labeling index of mammary tumors was significantly decreased in both biochanin A‐supplemented diet groups compared to the control. The present results indicate that soybeans, miso, and biochanin A are useful for the prevention of mammary cancer.

Mutations in the RAD54 recombination gene in primary cancers

Association of a recombinational repair protein RAD51 with tumor suppressors BRCA1 and BRCA2 suggests that defects in homologous recombination are responsible for tumor formation. Also recent findings that a protein associated with the MRE11/RAD50 repair complex is mutated in Nijmegen breakage syndrome characterized by increased cancer incidence and ionizing radiation sensitivity strongly support this idea. However, the direct roles of BRCA proteins and the protein responsible for NBS in recombinational repair are not clear though they are associated with the recombinational repair complexes. Since RAD51 forms a complex with other members of the RAD52 epistasis group and with BRCA proteins, it is reasonable to ask if alterations of members of the RAD52 epistasis group lead to tumor development. Here we describe missense mutations at functional regions of RAD54 and the absence of the wild-type RAD54 expression resulting from aberrant splicing in primary cancers. Since RAD54 is a recombinational protein associated with RAD51, this is the first genetic evidence that cancer arises from a defect in repair processes involving homologous recombination.

Chemoprevention of N-nitroso-N-methylurea-induced rat mammary cancer by miso and tamoxifen, alone and in combination

We examined the effects of a Japanese fermented soybean product, miso, and tamoxifen (TAM), alone and in combination, on N‐nitroso‐N‐methylurea (MNU)‐induced rat mammary cancer. Seven‐week‐old female CD/Crj rats received a single i.v. dose (50 mg/kg body weight) of MNU. After administration of MNU, the rats were divided into 4 groups: regular diet (control), 10% miso diet, regular diet+TAM, and 10% miso diet+TAM. TAM was implanted s.c. in the form of pellets containing 2.5 mg at the same time as MNU was administered. All rats were observed for 18 weeks after MNU administration. Incidence (percentage of rats with tumors) and multiplicity (mean tumors/rat) of mammary tumors were 91% and 4.5 in the control, 77% and 2.4 (P<0.05) in the 10% miso group, 68% and 1.4 (P<0.01) in the TAM group, and 10% (P<0.0001 or less) and 0.2 (P<0.0001) in the 10% miso+TAM group. In the second experiment, the effect of the combination of miso and TAM on established rat mammary tumors was investigated. When the mammary tumors induced by MNU reached 10 to 25 mm, the rats were divided into 3 treatment groups: regular diet, regular diet+TAM, and 10% miso diet+TAM. At 6 weeks after the start of treatment, the mean tumor size in the control and TAM groups was 160% and 141% of the pretreatment value, but a decrease to 85% of the pretreatment value was produced by the combination of miso and TAM, and this was significantly different from both the control and TAM groups (P<0.01 and P<0.05, respectively). These results indicate that miso is useful in protecting against mammary cancer and it can be expected to have a potent antitumor effect, especially when used in combination with TAM.

Factors related to anxiety and depression in women with breast cancer and their husbands: role of alexithymia and family functioning

Goals of workThe purpose of this study was to explore alexithymia, family functioning, and other factors that might affect anxiety and depression levels in women with breast cancer and in their husbands.Patients and methodsA cross-sectional study was undertaken in 46 postsurgical ambulatory women with breast cancer and their husbands. Documented informed consent for the study was obtained from each subject. All subjects completed the Zung self-rating anxiety scale (SAS), the Zung self-rating depression scale (SDS), the 20-item Toronto alexithymia scale (TAS-20), and the family assessment device (FAD).Main resultsMultiple regression analysis revealed that a high degree of alexithymia in patients correlated with a high degree of patient anxiety. Patient perceptions of inappropriate affective responsiveness among family members correlated with a high degree of depression. Among husbands, a high degree of anxiety was correlated with their own high level of alexithymia or low level of education, and with the occurrence of adjuvant therapy in their wives. Husband perceptions of inappropriate sharing of roles among family members, their own low education level, and a large number of family members correlated with high degrees of depression among them.ConclusionsThe present study revealed that alexithymia and family functioning are associated with anxiety and depression, respectively, in both women with breast cancer and in their husbands. Individual traits such as alexithymia and family functioning should be taken into account when we intervene to treat anxiety and depression in breast cancer patients and their husbands.

Mechanistic analysis of the antitumor efficacy of human natural killer cells against breast cancer cells

We investigated the role of human natural killer (NK) cells in the peripheral blood (PB) and liver in controlling breast cancer. The proportion of NK cells among liver mononuclear cells was significantly higher than among PB mononuclear cells. Liver NK cells inductively expressed higher levels of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) than PB NK cells in response to interleukin-2 (IL-2). Liver NK cells displayed higher cytotoxicity against various breast cancer cell lines (MDA-MB231, MDA-MB453, MDA-MB468, and MCF-7) after IL-2 stimulation than did PB NK cells. Anti-HER2 monoclonal antibody (mAb) promoted the cytotoxicity of both the types of NK cells toward HER2-expressing cell lines. All breast cancer cell lines highly expressed death-inducing TRAIL receptors, death receptor 4, but did not express death-inhibitory receptors (DcR1 and DcR2). Both PB and liver NK cell-induced cytotoxicity was inhibited partially by anti-TRAIL mAb and more profoundly by the combination of anti-TRAIL mAb and concanamycin A, indicating that TRAIL and perforin are involved. IL-2-stimulated liver and PB NK cells exhibited upregulated expression of CXCR3, which bind to the chemokines CXCL9, CXCL10, and CXCL11 secreted by breast cancer cells. We also found that IFN-γ promoted the production of CXCL10 from breast cancer cells. The results of this study show that IFN-γ secreted from NK cells likely promotes the production of CXCL10 from breast cancer cells, which in turn accelerates the migration of CXCR3-expressing NK cells into the tumor site. These findings suggest the possibility of a therapeutic approach by either activation of endogenous PB and liver NK cells or adoptive transfer of in vitro-activated autologous NK cells.

Feasibility and efficacy of speed‐feedback therapy with a bicycle ergometer on cognitive function in elderly cancer patients in Japan

We conducted this study with the aim of demonstrating the feasibility and efficacy of speed‐feedback therapy with a bicycle ergometer on cognitive function in elderly cancer patients.

Memorial Sloan-Kettering Cancer Center Nomogram to predict the risk of non-sentinel lymph node metastasis in Japanese breast cancer patients

PurposeAxillary lymph node dissection (ALND) remains the standard procedure for breast cancer patients with sentinel lymph node (SLN) metastasis; however, additional nodal metastasis is detected in completion ALND in only about 50% of these patients. To identify the risk of non-SLN metastasis, the Memorial Sloan-Kettering Cancer Center (MSKCC) developed a nomogram. Many validation studies have been performed to evaluate the accuracy of the nomogram in Western populations, but not in Asians. We conducted this study to establish the accuracy of the nomogram in a Japanese population.MethodsThe accuracy of the MSKCC nomogram for predicting non-SLN status was tested in 116 consecutive SLN-positive patients in our hospital. We then compared the findings of the source MSKCC study with those of our study. A receiver operating characteristics (ROC) curve was plotted, and the area under the curve (AUC) was calculated to assess the discriminative power.ResultsDespite the differences between our patients and the source population in many respects, the area under the ROC curve was 0.73, which was comparable to that obtained in the study on the source population.ConclusionsThe MSKCC nomogram provides a fairly accurate predicted probability for the likelihood of non-SLN metastases. Accordingly, it served as a useful tool for our Japanese patients with SLN metastases.

Evidence for centrally induced cholinergic vasodilatation in skeletal muscle during voluntary one‐legged cycling and motor imagery in humans

We have recently reported that central command contributes to increased blood flow in both noncontracting and contracting vastus lateralis (VL) muscles at the early period of voluntary one‐legged cycling. The purpose of this study was to examine whether sympathetic cholinergic vasodilatation mediates the increases in blood flows of both muscles during one‐legged exercise. Following intravenous administration of atropine (10 μg/kg), eight subjects performed voluntary 1‐min one‐legged cycling (at 35% of maximal voluntary effort) and mental imagery of the exercise. The relative concentrations of oxygenated‐ and deoxygenated‐hemoglobin (Oxy‐ and Deoxy‐Hb) in the bilateral VL were measured as an index of muscle tissue blood flow with near‐infrared spectroscopy (NIRS). The Oxy‐Hb in both noncontracting and contracting VL increased at the early period of one‐legged cycling, whereas the Deoxy‐Hb did not alter at that period. Atropine blunted (P < 0.05) the Oxy‐Hb responses of both VL muscles but did not affect the Deoxy‐Hb responses. The time course and magnitude of the atropine‐sensitive component in the Oxy‐Hb response were quite similar between the noncontracting and contracting VL muscles. With no changes in the Deoxy‐Hb and hemodynamics, imagery of one‐legged cycling induced the bilateral increases in the Oxy‐Hb, which were completely abolished by atropine. In contrast, imagery of a circle (with no relation to exercise) did not alter the NIRS signals, irrespective of the presence or absence of atropine. It is concluded that central command evokes cholinergic vasodilatation equally in bilateral VL muscles during voluntary one‐legged cycling and motor imagery.

Comparison of immunohistochemistry assays and real-time reverse transcription-polymerase chain reaction for analyzing hormone receptor status in human breast carcinoma

The estrogen receptor (ER) and progesterone receptor (PgR) status of 163 surgical breast cancer specimens determined on real‐time quantitative reverse transcription–polymerase chain reaction (RT‐PCR) using frozen tumor tissue were compared with that determined using three automated immunohistochemistry (IHC) assays including Dako (Glostrup, Denmark), Ventana (Tucson, AZ, USA) and BioGenex (San Ramon, CA, USA) assay. All specimens were semiquantified according to the Allred score and J‐score. The cut‐offs for ER determined by log (ER/glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH)) were −3.6 and −3.2 based on the Allred score and J‐score, respectively, and those for PgR determined by log (PgR/GAPDH) were −3.2 and −2.8, respectively. The Allred total score (TS) and the J‐score for ER and PgR on IHC were significantly correlated with the result on RT‐PCR (P < 0.00001). There was a high degree of concordance among ER and PgR status on IHC and those on RT‐PCR, suggesting that RT‐PCR is a useful method for evaluation of ER and PgR status. Some discrepancies between the IHC and RT‐PCR results were identified, however. Accordingly, further studies of RT‐PCR assays for hormone receptor (HR) are necessary with regard to biological behavior and responsiveness to hormone therapy.

Differential contribution of ACh‐muscarinic and β‐adrenergic receptors to vasodilatation in noncontracting muscle during voluntary one‐legged exercise

We have demonstrated the centrally induced cholinergic vasodilatation in skeletal muscle at the early period of voluntary one‐legged exercise and during motor imagery in humans. The purpose of this study was to examine whether central command may also cause β‐adrenergic vasodilatation during the exercise and motor imagery. Relative changes in oxygenated hemoglobin concentration (Oxy‐Hb) of bilateral vastus lateralis (VL) muscles, as index of tissue blood flow, and femoral blood flow to nonexercising limb were measured during one‐legged cycling and mental imagery of the exercise for 1 min before and after propranolol (0.1 mg/kg iv). The Oxy‐Hb of noncontracting muscle increased (P < 0.05) at the early period of exercise and the increase was sustained throughout exercise, whereas the Oxy‐Hb of contracting muscle increased at the early period but thereafter decreased. We subtracted the Oxy‐Hb response with propranolol from the control response in individual subjects to identify the propranolol‐sensitive component of the Oxy‐Hb response during exercise. In both noncontracting and contracting VL muscles, the increase in Oxy‐Hb at the early period of one‐legged exercise did not involve a significant propranolol‐sensitive component. However, as the exercise proceeded, the propranolol‐sensitive component of the Oxy‐Hb response was developed during the later period of exercise. Propranolol also failed to affect the initial increases in femoral blood flow and vascular conductance of nonexercising leg but significantly attenuated (P < 0.05) their later increases during exercise. Subsequent atropine (10–15 μg/kg iv) abolished the initial increases in Oxy‐Hb of both VL muscles. Mental imagery of the one‐legged exercise caused the bilateral increases in Oxy‐Hb, which were not altered by propranolol but abolished by subsequent atropine. It is likely that the rapid cholinergic and delayed β‐adrenergic vasodilator mechanisms cooperate to increase muscle blood flow during exercise.