Survival of Lung Cancer Patients Dependent on the LOH Status for DMP1, ARF, and p53

Lung cancer is the leading cause of cancer deaths in the world, and accounts for more solid tumor deaths than any other carcinomas. The prognostic values of DMP1, ARF, and p53-loss are unknown in lung cancer. We have conducted survival analyses of non-small cell lung cancer (NSCLC) patients from the University of Minnesota VA hospital and those from the Wake Forest University Hospital. Loss of Heterozygosity (LOH) for hDMP1 was found in 26 of 70 cases (37.1%), that of the ARF/INK4a locus was found in 33 of 70 (47.1%), and that of the p53 locus in 43 cases (61.4%) in the University of Minnesota samples. LOH for hDMP1 was associated with favorable prognosis while that of p53 predicted worse prognosis. The survival was much shorter for ARF-loss than INK4a-loss, emphasizing the importance of ARF in human NSCLC. The adverse effect of p53 LOH on NSCLC patients' survival was neutralized by simultaneous loss of the hDMP1 locus in NSCLC and breast cancer, suggesting the possible therapy of epithelial cancers with metastatic ability.

Stabilization of the p53-DNA Complex by the Nuclear Protein Dmp1α

We recently reported the existence of a physical interaction between the Myb-like transcription factor Dmp1 (Dmtf1) and p53 in which Dmp1 antagonized polyubiquitination of p53 by Mdm2 and promoted its nuclear localization. Dmp1 significantly stabilized p53-DNA complexes on promoters that contained p53-consensus sequences, which were either supershifted or disrupted with antibodies to Dmp1. Lysates from mice injected with doxorubicin showed that Dmp1 bound to p21Cip1, Bbc3, and Thbs1 gene regulatory regions in a p53-dependent fashion. Our data suggest that acceleration of DNA-binding of p53 by Dmp1 is a critical process for Dmp1 to increase the p53 function in Arf-deficient cells.

[Incomplete self-castration by the patient with gender identify disorder: a case report]

A 29-year-old man with gender identify disorder presented to our hospital complaining of scrotal pain. Two hours before the consultation, he tried to do self-castration by himself, but he stopped due to bleeding and scrotal pain. His testes were not removed, and his scrotal wound was closed at the emergency operation under spinal anesthesia. After the operation, he never repeated the same act.

Renal cell carcinoma with a novel germ-line mutation in isocitrate dehydrogenase 1 (IDH1) and its functional study

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Background: Recently, omics study such as metabolome analysis and whole genome sequencing has been applied to various disorders. We predicted the dysfunction of isocitrate dehydrogenase 1 (IDH1) in renal cell carcinoma (RCC) using metabolome analysis and identified a novel mutation of IDH1. In addition, we examined its function. Methods: We determined the global-scale metabolome profiling of human RCC by capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS), and compared the metabolite levels of tumors and paired normal tissues in 10 patients with RCC. We performed the genotyping of IDH1 and von Hippel-Lindau (VHL) gene. We also performed transfection experiments by using Lipofectamine and measured the enzymatic activity of IDH1 in RCC cell lines. All protocols were performed by the Institutional Review Board (IRB) of Hamamatsu University School of Medicine and Keio University. Informed consent was obtained from the patient in accordance with the IRB of Hamamatsu University School of Medicine. Results: The acceleration of glycolysis with low level of NADPH and citrate in one patient led to IDH1 dysfunction followed by identifying a novel missense mutation, V178I. In transfection experiment, the reductive activity of IDH1 variant (V178I) increased 2.5 times than that of IDH1 wild type while the oxidative activity of IDH1 variant oxidative activity was as well as that of IDH1 wild type. Furthermore, in the metabolome analysis using labeling glutamine, RCC cell lines deficient in the von Hippel-Lindau (VHL) protein preferentially use reductive glutamine metabolism. On the other hand, this patient with V178I mutation of IDH1 had no VHL mutation. Conclusions: Metabolome analysis led to the identification a novel IDH1 missense mutation in RCC. This mutation might be involved with acceleration of reductive reaction in tricarboxylic acid cycle. Metabolome analysis using CE-TOFMS could be a powerful tool for the global-scale exploration of disease-specific metabolism.

Axitinib controlled metastatic renal cell carcinoma for 5 years

We present two patients with a long-term response to axitinib for cytokine-refractory metastatic renal cell carcinoma. One patient has had a continuing partial response for 58 months with cytokine-intolerant metastatic renal cell carcinoma and the other patient has had continuing stable disease accompanied by a mixed response for 57 months with cytokine-refractory and intolerant metastatic renal cell carcinoma. The condition of hypertension as an adverse event markedly depended on whether or not axitinib was administered. The patients responded to axitinib with an elevation of diastolic blood pressure to 90 mmHg or higher until 2 weeks after starting axitinib. To get a long-term response to axitinib, it may be important to control well the balance between treatment effect and adverse events while using drug withdrawal.

[Bilateral adrenal hemorrhage due to adrenal metastasis of lung cancer]

A 58-year-old man presented with nausea and left flank pain. The patient was referred to our hospital based on clear detection of anemia and computed tomography findings of bilateral adrenal tumors with hemorrhage and a mass in the apex of the left lung. Right adrenal artery embolization had no effect on enlargement of the right adrenal hematoma or advanced anemia. Right adrenalectomy was then performed in an attempt to control hemorrhaging and make a definitive diagnosis, and the patient's anemia improved following the operation. Histopathological diagnosis suggested adrenal metastasis of lung adenocarcinoma, which was subsequently diagnosed given similarities in transbronchial biopsy findings to those in the right adrenal gland. Adrenal hemorrhage due to metastasis of lung cancer is an extremely rare condition; indeed, to our knowledge, the present case is only the 26th reported worldwide. However, prognosis for this mortal condition may be improved should patients receive adrenalectomy followed by an appropriate treatment regimen.

Prognostic value of the hDMP1-ARF-Hdm2-p53 pathway in breast cancer

Our recent study showed critical roles of Dmp1 as a sensor of oncogenic Ras, HER2/neu signaling and activation of the Arf-p53 pathway. To elucidate the role of human DMP1 (hDMP1) in breast cancer, one hundred and ten pairs of human breast cancer specimen were studied for the alterations of the hDMP1-ARF-Hdm2-p53 pathway with follow up of clinical outcomes. Loss of heterozygosity (LOH) of the hDMP1 locus was found in 42% of human breast carcinomas, while that of INK4a/ARF and p53 were found in 20 and 34%, respectively. Hdm2 amplification was found in 13% of the same sample, which was found independently of LOH for hDMP1. Conversely, LOH for hDMP1 was found in mutually exclusive fashion with that of INK4a/ARF and p53, and was associated with low Ki67 index and diploid karyotype. Consistently, LOH for hDMP1 was associated with luminal A category and longer relapse-free survival, while that of p53 was associated with non-luminal A and shorter survival. Thus, loss of hDMP1 could define a new disease category associated with prognosis of breast cancer patients. Human breast epithelial cells/cancer cells with wild-type p53 were sensitive to growth inhibition by activated Dmp1:ER while those that delete p14(ARF) or p53, and/or Hdm2 amplification showed partial or nearly complete resistance, indicating that p53 is a critical target for hDMP1 to exhibit its biological activity.

Dmp1 physically interacts with p53 and positively regulates p53's stability, nuclear localization, and function

The transcription factor Dmp1 is a Ras/HER2-activated haplo-insufficient tumor suppressor that activates the Arf/p53 pathway of cell-cycle arrest. Recent evidence suggests that Dmp1 may activate p53 independently of Arf in certain cell types. Here, we report findings supporting this concept with the definition of an Arf-independent function for Dmp1 in tumor suppression. We found that Dmp1 and p53 can interact directly in mammalian cells via the carboxyl-terminus of p53 and the DNA-binding domain of Dmp1. Expression of Dmp1 antagonized ubiquitination of p53 by Mdm2 and promoted nuclear localization of p53. Dmp1-p53 binding significantly increased the level of p53, independent of the DNA-binding activity of Dmp1. Mechanistically, p53 target genes were activated synergistically by the coexpression of Dmp1 and p53 in p53(-/-);Arf(-/-) cells, and genotoxic responses of these genes were hampered more dramatically in Dmp1(-/-) and p53(-/-) cells than in Arf(-/-) cells. Together, our findings identify a robust new mechanism of p53 activation mediated by direct physical interaction between Dmp1 and p53.

Evaluation of the expression levels of S100A2 mRNA in renal cell carcinoma

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Background: The human S100 proteins are a calcium-binding protein comprising around 20 sort, at least 16 of these genes included pseudogenes are clustering to chromosome 1q21 , known as the epidermal differentiation complex. We have reported that S100A1 and A10 are expressed in human renal cell carcinoma (RCC) (Teratani T et al; Cancer Lett 2002, Teratani T, et al; BBRC 2002, Domoto, et al Cancer Sci. 2007). Diminished expression of S100A2 has been reported in some kinds of cancers (ex. lung, breast, prostate), but not reported in renal cell carcinoma (RCC). The aim of the present study is to evaluate the expression level S100A2 mRNA in human renal cell carcinoma.

Methods: Sixty-one patients, pathologically diagnosed for clear cell RCC performed nephrectomy, were used in this study. Genomic DNA and RNA were extracted from RCC part and matched normal part in each patient. First-strand cDNA was synthesized from 2 micrograms RNA using Superscript-2 reverse transcriptase (Invitorgen), and reverse transcription polymerase chain reaction (RT-PCR) were performed using specific primers for S100A2. We also check the CpG methylation in the promoter region of the S100A2 gene using COBRA assay (combined bisulfite restriction analysis).

Results: 45 cases (73%) showed decreased S100A2 expression in RCC parts. In53 cases of clear cell RCC, S100A2 expression decreased in fourty-two (79%) cases. In contrast clear cell RCC, 5 cases showed expression S100A2 in non-clear RCC (8cases; 62%), and 2 cases of clear cell RCC in VHL disease patients also had expression of S100A2. 30 cases of clear cell RCC were used in COBRA assay, S100A2 methylation were seen in all cases.

Conclusions: Diminished expression of S100A2 is frequently shows in RCC, especially clear cell RCC. It suggests that property of clear cell RCC is different from other type of RCC.

Should ipsilateral solitary adrenal involvement in renal cell carcinoma be staged as M1?

OBJECTIVE

In 2009, the TNM classification of malignant tumors was revised, and the renewal of the T2-4 stage in renal cell carcinoma was adopted. To date, however, the staging of ipsilateral solitary adrenal involvement in renal cell carcinoma has not been sufficiently evaluated.

METHODS

We retrospectively reviewed the adrenal involvement in renal cell carcinoma among 1033 patients admitted to the Department of Urology at Hamamatsu University Hospital, Japan, and affiliated hospitals between 1978 and 2007.

RESULTS

We identified 23 of the 1033 patients (2.2%) with adrenal involvement in renal cell carcinoma. In renal cell carcinoma patients with adrenal involvement, a tendency for a high histological grade of tumor and lower overall survival (P< 0.0001) was observed. Ipsilateral solitary adrenal involvement was detected in 4 of the 23 patients (15%), whereas 2 of the 23 (9%) had direct invasion of the adrenal gland. All tumors in the 14 patients without ipsilateral solitary adrenal involvement and recurrent adrenal tumors were classified as Stage IV. The TNM classification of the four renal cell carcinoma patients with ipsilateral solitary adrenal involvement was determined to be either pT3N0M0 or pT1-3N0M1. Among the four patients with ipsilateral solitary adrenal involvement, three patients had recurrent tumors, despite complete surgical resection. Two of these patients died of metastatic renal cell carcinoma after 2 and 10 years of radical nephrectomy, respectively, whereas one was still alive with cancer 3 years after the initial radical nephrectomy. The fourth had no recurrence of renal cell carcinoma, but did develop synchronous gall bladder cancer (pT2N0M0) and bile duct cancer (pT2N0M0).

CONCLUSIONS

Adrenal involvement in primary renal cell carcinoma was observed more frequently in patients with advanced tumor stages. In the TNM classification system, we propose that ipsilateral solitary adrenal involvement in renal cell carcinoma should be staged as M1.

Abstract 2958: Cyclin D1 regulates the ARF and INK4a promoters

Cyclin D1 is a member of cyclin protein family, which drives the cell cycle transition from G1 to S phase. The cyclin D1 protein is overexpressed in ∼50% of human breast cancers and is associated with short survival of patients when the gene is amplified. Cyclin D1 forms holoenzymes with cyclin-dependent protein kinase (Cdk) 4 and 6, and the Cyclin D-Cdk4/6 complex phosphorylates and inactivates the pRb retinoblastoma tumor suppressor, releasing E2F transcriptional factors from Rb inhibition. The pRb phosphorylation is blocked by p16INK4a, encoded by the CDKN2A locus, which inhibits the kinase activity of Cyclin D-Cdk4/6 complex. The CDKN2A locus also encodes another tumor suppressor protein named p14ARF (p19Arf in mouse), which stabilizes p53 by inhibiting MDM2-dependent degradation. Previous studies from our laboratory showed that the cyclin D1 collaborated with the Dmp1 (cyclin D binding myb-like protein 1) tumor suppressor to activate the Arf promoter. To further demonstrate the effect of cyclin D1 on p19Arf and p16Ink4a promoter activity, NIH 3T3 cells and MEF cells were transfected a construct expressing the luciferase reporter gene linked with the Arf promoter together with vector or cyclin D1. Using luciferase reporter assay, we found that the Arf promoter was activated upon cyclin D1 overexpression in both cell lines, and the activation was abrogated when cells were co-transfected with E2F-DB, which displaces endogenous E2Fs and acts in a dominant-negative manner. Consistent with reporter assays, the Arf mRNA was increased in MEFs overexpressing cyclin D1, compared to those infected with vector only. By performing chromatin immunoprecipitation in tumors of mammary gland from MMTV-neu transgenic mice that overexpress cyclin D1, we found that cyclin D1 can interact with the Arf promoter although it cannot directly bind to the Arf promoter region in electrophoretic mobility shift assay using recombinant cyclin D1 protein. To identify the effect of cyclin D1 on p16Ink4a promoter, we performed luciferase reporter assay in NIH 3T3 cells by co-transfecting Ink4a promoter together with vector or cyclin D1. We found that the Ink4a promoter activity was increased upon cyclin D1 overexpression, and the activation was not abrogated when cells were transfected with cyclin D1-K114E that does not bind to CDK4. Taken together, our data suggest that overexpression of cyclin D1 activates both p19Arf and p16Ink4a promoters to prevent neoplastic growth of incipient cancer cells, and the activation is mediated by indirect binding of cyclin D1 to the promoter regions. We are currently mapping the cyclin D1-responsive elements on the Arf and Ink4a promoters to identify transcription factors responsible for Arf/Ink4a induction by cyclin D1.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2958. doi:10.1158/1538-7445.AM2011-2958

Abstract 3076: MEKK1 is a novel modulator of the Arf-p53 pathway via Dmp1 phosphorylation

Dmp1 (cyclin D-interacting myb-like protein 1; Dmtf1) is a transcription factor isolated in yeast two-hybrid screen as a cyclin D2 binding partner. As a transcription factor, Dmp1 binds to nonameric DNA consensus sequences CCCG(G/T)ATG(T/C) to act as an activator or a repressor. Extensive molecular and genetic evidence links tumor suppressor function of Dmp1 to regulation of the ARF-p53 pathway. In fact, Dmp1 directly binds to p19Arf (p14ARF in humans) promoter and induces its expression. Increase in ARF level leads to protection of p53 from Mdm2-mediated degradation and subsequent increase in p53 target genes involved in cell cycle arrest and apoptosis. Oncogenic Ras and Her2/neu induce Dmp1 expression leading to Arf-, p53-dependent cell cycle arrest. Human DMP1 locus is hemizygously deleted in ∼50% of breast carcinomas, which is mutually exclusive of ARF and p53 loss. Based on the amino acid sequence, predicted molecular weight of Dmp1 is 85kDa. However, Dmp1 migrates to ∼120-130kDa on a SDS-PAGE gel, suggesting post-translational modifications. Although signal transduction pathways regulating Dmp1 transcripton have been studied, the role of Dmp1 protein modification is unknown. Treatment of Dmp1 protein with calf intestine phosphatase and running a 2D SDS-PAGE gel, we have shown that one mode of post-translational modification is via phosphorylation. The presence of phosphates on several Serines and/or Threonines was confirmed with mass spectrometry. Using an Arf luciferase reporter assay in 3T3 cells, we found that MEKK1 (MEK kinase 1) synergizes with Dmp1 on the Arf promoter activity, with the synergy attenuated when several of the putative phosphorylation sites on Dmp1 were mutated. The effect observed was Dmp1-dependent since MEKK1 was unable to activate the Arf promoter in Dmp1-null cells. Full length (inactive) MEKK1 was unable to synergize with Dmp1 on the Arf promoter activity suggesting necessity of the kinase activity. The ability of MEKK1 to directly phosphorylate Dmp1 was confirmed in in vitro kinase assay using purified MEKK1 and Flag-Dmp1 proteins and Arf reporter assays where known kinases downstream of MEKK1(MEK1, MEK4/7, JNK1/2) were inhibited or knocked down. MEKK1 and Dmp1 co-immunoprecipitated when expressed in 3T3 cells. To study the effect of MEKK1 on endogenous Dmp1 and Arf, we either expressed MEKK1 or treated cells with MEKK1-activating drugs, cisplatin and etoposide. In this setting, endogenous p14ARF was induced and the banding pattern of Dmp1 protein was shifted in a SDS-PAGE gel indicating protein modification. Here we show that Dmp1 can be directly phosphorylated by MEKK1 to modulate Dmp1 transcriptional activity on the Arf promoter. Therefore, MEKK1 may activate the Arf-p53 pathway via direct Dmp1 protein phosphorylation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3076. doi:10.1158/1538-7445.AM2011-3076

Critical roles of DMP1 in human epidermal growth factor receptor 2/neu-Arf-p53 signaling and breast cancer development

Human epidermal growth factor receptor 2 (HER2) overexpression stimulates cell growth in p53-mutated cells while it inhibits cell proliferation in those with wild-type p53, but the molecular mechanism is unknown. The Dmp1 promoter was activated by HER2/neu through the phosphatidylinositol-3'-kinase-Akt-NF-κB pathway, which in turn stimulated Arf transcription. Binding of p65 and p52 subunits of NF-κB was shown to the Dmp1 promoter and that of Dmp1 to the Arf promoter on HER2/neu overexpression. Both Dmp1 and p53 were induced in premalignant lesions from mouse mammary tumor virus-neu mice, and mammary tumorigenesis was significantly accelerated in both Dmp1+/- and Dmp1-/- mice. Selective deletion of Dmp1 and/or overexpression of Tbx2/Pokemon was found in >50% of wild-type HER2/neu carcinomas, although the involvement of Arf, Mdm2, or p53 was rare. Tumors from Dmp1+/-, Dmp1-/-, and wild-type neu mice with hemizygous Dmp1 deletion showed significant downregulation of Arf and p21Cip1/WAF1, showing p53 inactivity and more aggressive phenotypes than tumors without Dmp1 deletion. Notably, endogenous hDMP1 mRNA decreased when HER2 was depleted in human breast cancer cells. Our study shows the pivotal roles of Dmp1 in HER2/neu-p53 signaling and breast carcinogenesis.

Classical and Novel Prognostic Markers for Breast Cancer and their Clinical Significance

The use of biomarkers ensures breast cancer patients receive optimal treatment. Established biomarkers such as estrogen receptor (ER) and progesterone receptor (PR) have been playing significant roles in the selection and management of patients for endocrine therapy. HER2 is a strong predictor of response to trastuzumab. Recently, the roles of ER as a negative and HER2 as a positive indicator for chemotherapy have been established. Ki67 has traditionally been recognized as a poor prognostic factor, but recent studies suggest that measurement of Ki67-positive cells during treatment will more effectively predict treatment efficacy for both anti-hormonal and chemotherapy. p53 mutations are found in 20–35% of human breast cancers and are associated with aggressive disease with poor clinical outcome when the DNA-binding domain is mutated. The utility of cyclin D1 as a predictor of breast cancer prognosis is controversial, but cyclin D1b overexpression is associated with poor prognosis. Likewise, overexpression of the low molecular weight form of cyclin E1 protein predicts poor prognosis. Breast cancers from BRCA1/2 carriers often show high nuclear grades, negativity to ER/PR/HER2, and p53 mutations, and thus, are associated with poor prognosis. The prognostic values of other molecular markers, such as p14^ARF, TBX2/3, VEGF in breast cancer are also discussed. Careful evaluation of these biomarkers with current treatment modality is required to determine whether their measurement or monitoring offer significant clinical benefits.

Abstract 1096: Arf-independent activation of p53 by the Dmp1 tumor suppressor

Cyclin D binding myb-like protein 1 (Dmp1; Dmtf1) is a tumor suppressor that is deleted in ∼40 % of human non-small cell lung carcinomas. The Dmp1 promoter receives signals from oncogenic Ras and the protein shows its activity as a tumor suppressor by directly binding and transactivating the Arf promoter, and thereby inducing Arf-, p53-dependent cell cycle arrest. Both Eµ-Myc and K-rasLA-induced tumor development was accelerated in Dmp1+/− and Dmp1−/− mice, suggesting that Dmp1 is haplo-insufficient for tumor suppression. In Eµ-Myc lymphomas, the combined frequencies of p53 mutation and Arf deletion in the Dmp1+/− or Dmp1−/− mice were significantly lower (∼10 %) than that in Dmp1+/+ littermates (∼50 %), indicating that Dmp1 is a physiological regulator of the Arf-p53 pathway in vivo. We recently found that the frequency of p53 mutation (∼40 %) was significantly decreased in both Dmp1+/− and Dmp1−/− backgrounds (&lt; 10 %) in the K-rasLA lung cancer model where the Ink4a/Arf involvement is very rare. Moreover, our recent data show that Dmp1 physically interacts with p53 to neutralize the activity of Hdm2. To demonstrate the Arf-independent function of Dmp1 on p53 activation in vivo, we injected doxorubicin into wild-type, Arf-null, and Dmp1-null mice, harvested the thymus at 2 hr intervals, and studied the expression of the p53 targets, p21cip1 and bbc3, by real-time PCR and immunohistochemistry. Thymus was chosen as a target tissue since Dmp1 is highly expressed in the medulla in our histochemical studies. Western blotting analyses with DO-1 and phosphoserine-specific antibodies verified p53 activation by doxorubicin. Cleaved caspase 3 was detectable in the thymic medulla of wild-type mice 6 hrs after tail injection of doxorubicin, indicating the induction of apoptotic cell death by the genotoxic drug. Cleaved caspase 3 staining was significantly decreased in the thymus from Arf−/− mice as compared to wild-type mice, but the staining was even lower in Dmp1−/− mice. Consistent with these findings, the p21cip1 mRNA induction (∼23-fold increase in wild-type mice) was more significantly compromised in Dmp1−/− mice (∼7-fold) than in Arf−/− mice (∼15-fold). Bbc was undetectable in Dmp1−/− thymus even 4-6 hrs after injection of doxorubicin while it was significantly induced (∼3-fold) in both wild-type and Arf−/− mice. These mRNA data were confirmed by immunohistochemical staining of thymic tissues with p21cip1 and bbc3-specific antibodies. Together, our data demonstrate the Arf-independent activation of p53 by Dmp1 in response to genotoxic stress in vivo. We are currently conducting the same series of experiments in the mouse lung.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1096.

The Arf-inducing transcription factor Dmp1 encodes a transcriptional activator of amphiregulin, thrombospondin-1, JunB and Egr1

Dmp1 (Dmtf1) encodes a Myb-like transcription factor implicated in tumor suppression through direct activation of the Arf-p53 pathway. The human DMP1 gene is frequently deleted in non-small cell lung cancers, especially those that retain wild-type INK4a/ARF and/or p53. To identify novel genes that are regulated by Dmp1, transcriptional profiles of lung tissue from Dmp1-null and wild-type mice were generated using the GeneChip Microarray. Comparative analysis of gene expression changes between the two groups resulted in identification of numerous genes that may be regulated by Dmp1. Notably, amphiregulin (Areg), thrombospondin-1 (Tsp-1), JunB, Egr1, adrenomedullin (Adm), Bcl-3 and methyl-CpG binding domain protein 1 (Mbd1) were downregulated in the lungs from Dmp1-null mice while Gas1 and Ect2 genes were upregulated. These target genes were chosen for further analyses since they are involved in cell proliferation, transcription, angiogenesis/metastasis, apoptosis, or DNA methylation, and thus could account for the tumor suppressor phenotype of Dmp1. Dmp1 directly bound to the genomic loci of Areg, Tsp-1, JunB and Egr1. Significant upregulation or downregulation of the novel Dmp1 target genes was observed upon transient expression of Dmp1 in alveolar epithelial cells, an effect which was nullified by the inhibition of de novo mRNA synthesis. Interestingly, these genes and their protein products were significantly downregulated or upregulated in the lungs from Dmp1-heterozygous mice as well. Identification of novel Dmp1 target genes not only provides insights into the effects of Dmp1 on global gene expression, but also sheds light on the mechanism of haploid insufficiency of Dmp1 in tumor suppression.

MMTV mouse models and the diagnostic values of MMTV-like sequences in human breast cancer

Mouse mammary tumor virus (MMTV) long terminal repeat (LTR)-driven transgenic mice are excellent models for breast cancer as they allow for the targeted expression of various oncogenes and growth factors in neoplastic transformation of mammary glands. Numerous MMTV-LTR-driven transgenic mouse models of breast cancer have been created in the past three decades, including MMTV-neu/ErbB2, cyclin D1, cyclin E, Ras, Myc, int-1 and c-rel. These transgenic mice develop mammary tumors with different latency, histology and invasiveness, reflecting the oncogenic pathways activated by the transgene. Recently, homologous sequences of the env gene of MMTV have been identified in approximately 40% of human breast cancers, but not in normal breast or other types of cancers, suggesting possible involvement of mammary tumor virus in human breast carcinogenesis. Accumulating evidence demonstrates the association of MMTV provirus with progesterone receptor, p53 mutations and advanced-stage breast cancer. Thus, the detection of MMTV-like sequences may have diagnostic value to predict the clinical outcome of breast cancer patients.

High levels of thymidine phosphorylase as an independent prognostic factor in renal cell carcinoma

BACKGROUND

We investigated whether thymidine phosphorylase (TP) protein level in renal cell carcinoma (RCC) correlates with clinicopathological characteristics and clinical outcomes.

METHODS

TP protein level was measured in 116 RCC specimens and in 90 non-neoplastic kidney tissues using a sandwich-type enzyme-linked immunosolvent assay.

RESULTS

The median TP protein level in RCC tissues was 9.76-fold (range, 3.2-933.9) higher than those in non-neoplastic kidney tissues (P < 0.0001). TP protein level was correlated with T classification, histological grade and mode of infiltration. TP as a prognostic variable was studied using a logistic regression model. TP at higher levels (128 U/mg protein or greater) would play a role as an independent prognostic factor (odds ratio, 13.73; 95% confidence interval, 2.09-90.41; P = 0.0064).

CONCLUSION

TP at high levels can be regarded as an unfavorable independent prognostic factor. These results may pave a way for a novel approach to effective treatment of RCC.

[Interferon-based cytokine therapy for advanced renal cell carcinoma]

Among 126 patients diagnosed with metastatic renal cell carcinoma at Hamamatsu University or its affiliated hospital between 1978 and 2004, pretreatment features associated with a shorter survival in the multivariate analysis were in symptomatic status at diagnosis and in multiple organ metastasis. The 1- and 3-year survival rate in patients with these two prognostic factors were 22.3 and 0.3%, respectively. The style of treatment did not influenced survival in these patients. Therefore, an accurate assessment of their survival benefits both them and physician while it is urgent that we develop novel agents and strategy.

Left atrial myxoma presenting with erythematous macules and loss of memory

Left atrial myxoma was diagnosed in a 42-year-old woman who had cutaneous and neurological manifestations without cardiac symptoms or signs. A two-dimensional echocardiogram revealed an orange-sized mobile mass in the left atrium. Magnetic resonance imaging showed multiple cerebral infarctions. Cardiac surgery for removal of the left atrial myxoma was successful and histopathology confirmed myxoma. Cutaneous and neurological manifestations were improved after the operation. Early surgical intervention may prevent the onset of severe neurological deficits in such patients.

Synthesis and quantitative structure-activity relationship analysis of N-triiodoallyl- and N-iodopropargylazoles. New antifungal agents

New series of N-(2,3,3-triiodoallyl) and N-(3-iodopropargyl) azole derivatives (100 compounds) involving pyrrole, pyrazole, imidazole, triazole, and tetrazole nuclei were synthesized successively with the aid of quantitative structure-activity relationship (QSAR) analysis to obtain potent antifungal agents. Starting from the derivatives of nitropyrrole-containing antibiotics, the QSAR analysis of the pyrrole derivatives against Candida albicans and Trichophyton mentagrophytes strains indicated the positive contribution of the nitro group and negative effect of the size of molecule. Further application of the QSAR analysis on the multi-azole derivatives revealed the importance of hydrophobicity and electronegativity as well as steric effect to the activities and led to the synthesis of one of the most potent iodo compounds, 2-(2,3,3-triiodoallyl)tetrazole (67, ME1401).

[Absorption, distribution, and excretion of arbekacin after intravenous and intramuscular administration in rats]

Absorption, distribution, and excretion of arbekacin (HBK) were studied in rats after intravenous or intramuscular administration of HBK at a dose of 10 mg/kg or 20 mg/kg. Elimination half-lives of HBK were 0.69 hour for bolus intravenous administration, 0.55 hour for constant rate intravenous infusion, and 0.57 hour for intramuscular administration. Cumulative urinary excretions within 24 hours after administration were 74.7% of the dose for bolus intravenous administration, and 79.1% of the dose for intramuscular administration. No significant difference was observed in the cumulative urinary excretions between the 2 administration routes. Cumulative biliary excretions within 24 hours after administration were around 0.1% of doses regardless administration routes, bolus intravenous or intramuscular administration. The tissue or organ distribution of HBK after bolus intravenous administration was similar to that after intramuscular administration. The drug was distributed most abundantly into the kidney followed by plasma and the lung. The distribution of the drug into the liver was the least among the 6 tissues or organs examined in this study. The protein binding of HBK was studied by an equilibrium dialysis method at three different concentrations of HBK, 5, 10, and 20 micrograms/ml. Binding ratios of HBK to human serum, human serum albumin, and rat serum were less than 15%.

Antibacterial activity and ototoxicity in guinea pigs, and nephrotoxicity in rats of arbekacin

Arbekacin (HBK), 1-N[(S)-4-amino-2-hydroxybutyl]-3',4'-dideoxykanamycin B, showed broad antibacterial spectra against gram-positive and gram-negative bacteria including Pseudomonas aeruginosa. It was also effective against gentamycin- or tobramycin-resistant bacteria. HBK was resistant to various aminoglycoside-inactivating enzymes except for AAC (2') and AAC (6')-IV, both of which slowly inactivated it. Even at higher dosages (150 mg/kg i.m. or greater, which resulted in some deaths), HBK never decreased the pinna reflex in guinea pigs, while 150 mg/kg or more of dibekacin (DKB) or amikacin (AMK) caused loss of this reflex. HBK has less ototoxicity than do DKB and AMK. This was confirmed by histopathological examination of the inner ear. The degree of nephrotoxicity of HBK was suggested to be similar to that of DKB as judged from serum biochemical tests, urinalysis, and histopathological findings.