ALK upregulates POSTN and WNT signaling to drive neuroblastoma

Neuroblastoma is the most common extracranial solid tumor of childhood. While MYCN and mutant anaplastic lymphoma kinase (ALKF1174L) cooperate in tumorigenesis, how ALK contributes to tumor formation remains unclear. Here, we used a human stem cell-based model of neuroblastoma. Mis-expression of ALKF1174L and MYCN resulted in shorter latency compared to MYCN alone. MYCN tumors resembled adrenergic, while ALK/MYCN tumors resembled mesenchymal, neuroblastoma. Transcriptomic analysis revealed enrichment in focal adhesion signaling, particularly the extracellular matrix genes POSTN and FN1 in ALK/MYCN tumors. Patients with ALK-mutant tumors similarly demonstrated elevated levels of POSTN and FN1. Knockdown of POSTN, but not FN1, delayed adhesion and suppressed proliferation of ALK/MYCN tumors. Furthermore, loss of POSTN reduced ALK-dependent activation of WNT signaling. Reciprocally, inhibition of the WNT pathway reduced expression of POSTN and growth of ALK/MYCN tumor cells. Thus, ALK drives neuroblastoma in part through a feedforward loop between POSTN and WNT signaling.

Use of DNA-alkylating pyrrole-imidazole polyamides for anti-cancer drug sensitivity screening in pancreatic ductal adenocarcinoma

BACKGROUND

Activating mutations of the KRAS occurs in >90% of pancreatic ductal adenocarcinoma (PDAC) cases. However, direct pharmacological targeting of the activated KRAS protein has been challenging. We previously reported that KR12, a DNA-alkylating pyrrole-imidazole polyamide designed to recognize the KRAS G12D/V mutation, showed an anti-tumor effect in colorectal cancer. In this study, we evaluated the anti-tumor effect of KR12 in PDAC.

METHODS

KR12 was synthesized by an automated peptide synthesizer PSSM-8 and tested for anti-tumor effect in PDAC mouse models.

RESULT

KR12 inhibited tumor growth in a spontaneous PDAC mouse model, although the anti-tumor activity appeared to be limited in a human PDAC xenograft model. We developed a pyrrole-imidazole polyamide screening process based on the hypothesis that genetic elements otherwise unaffected by KR12 could exert attenuating effects on KRAS-suppression-resistant PDAC. We identified RAD51 as a potential therapeutic target in human PDAC cells. A RAD51 inhibitor showed an inhibitory effect on cell growth and affected the cytotoxic activity of KR12 in PDAC cells.

CONCLUSION

These data suggested that the simultaneous inhibition of RAD51 and mutant KRAS blockage would be an important therapeutic strategy for PDAC.

CD133 prevents colon cancer cell death induced by serum deprivation through activation of Akt-mediated protein synthesis and inhibition of apoptosis

During the early phase of tumorigenesis, primary malignant cells survive within a low nutrition environment caused by a poorly organized vascular system. Here, we sought to determine the functional significance of CD133 in the survival of cancer cells under nutrient‐poor conditions. Knockdown and overexpression experiments demonstrated that CD133 suppresses colon cancer cell death induced by serum deprivation through activation of Akt‐mediated anti‐apoptosis and protein synthesis pathways. Furthermore, serum deprivation increased the amount of endogenous CD133 protein, which was regulated at least in part by phosphoinositide 3‐kinase. Thus, it is highly likely that CD133 contributes to the acquisition/maintenance of the resistance to stress arising from nutrient deficiency in early avascular tumor tissues.

Targeting the mutant PIK3CA gene by DNA-alkylating pyrrole-imidazole polyamide in cervical cancer

PIK3CA is the most frequently mutated oncogene in cervical cancer, and somatic mutations in the PIK3CA gene result in increased activity of PI3K. In cervical cancer, the E545K mutation in PIK3CA leads to elevated cell proliferation and reduced apoptosis. In the present study, we designed and synthesized a novel pyrrole-imidazole polyamide-seco-CBI conjugate, P3AE5K, to target the PIK3CA gene bearing the E545K mutation, rendered possible by nuclear access and the unique sequence specificity of pyrrole-imidazole polyamides. P3AE5K interacted with double-stranded DNA of the coding region containing the E545K mutation. When compared with conventional PI3K inhibitors, P3AE5K demonstrated strong cytotoxicity in E545K-positive cervical cancer cells at lower concentrations. PIK3CA mutant cells exposed to P3AE5K exhibited reduced expression levels of PIK3CA mRNA and protein, and subsequent apoptotic cell death. Moreover, P3AE5K significantly decreased the tumor growth in mouse xenograft models derived from PIK3CA mutant cells. Overall, the present data strongly suggest that the alkylating pyrrole-imidazole polyamide P3AE5K should be a promising new drug candidate targeting a constitutively activating mutation of PIK3CA in cervical cancer.

Vitamin K3 derivative induces apoptotic cell death in neuroblastoma via downregulation of MYCN expression

Neuroblastoma is a pediatric malignant tumor arising from the sympathetic nervous system. The patients with high-risk neuroblastomas frequently exhibit amplification and high expression of the MYCN gene, resulting in worse clinical outcomes. Vitamin K3 (VK3) is a synthetic VK-like compound that has been known to have antitumor activity against various types of cancers. In the present study, we have asked whether VK3 and its derivative, VK3-OH, could have the antitumor activity against neuroblastoma-derived cells. Based on our results, VK3-OH strongly inhibited cell proliferation and induced apoptotic cell death compared to VK3. Treatment of MYCN-driven neuroblastoma cells with VK3-OH potentiated tumor suppressor p53 accompanied by downregulation of anti-apoptotic Bcl-2 and Mcl-1. Interestingly, VK3-OH also suppressed the MYCN at mRNA and protein levels. Furthermore, we found downregulation of LIN28B following VK3-OH treatment in MYCN-amplified and overexpressed neuroblastoma cells. Collectively, our current findings strongly suggest that VK3-OH provides a potential therapeutic strategy for patients with MYCN-driven neuroblastomas.

PTPRK suppresses progression and chemo-resistance of colon cancer cells via direct inhibition of pro-oncogenic CD133

Receptor‐type protein tyrosine phosphatase κ (PTPRK) is considered to be a candidate tumor suppressor. PTPRK dephosphorylates CD133, which is a stem cell marker; phosphorylated CD133 accelerates xenograft tumor growth of colon cancer cells through the activation of AKT, but the functional significance of this has remained elusive. In this study, we have demonstrated that knockdown of PTPRK potentiates the pro‐oncogenic CD133–AKT pathway in colon cancer cells. Intriguingly, depletion of PTPRK significantly reduced sensitivity to the anti‐cancer drug oxaliplatin and was accompanied by up‐regulation of phosphorylation of Bad, a downstream target of AKT. Together, our present observations strongly suggest that the CD133–PTPRK axis plays a pivotal role in the regulation of colon cancer progression as well as drug resistance.

Depletion of pro-oncogenic RUNX2 enhances gemcitabine (GEM) sensitivity of p53-mutated pancreatic cancer Panc-1 cells through the induction of pro-apoptotic TAp63

Recently, we have described that siRNA-mediated silencing of runt-related transcription factor 2 (RUNX2) improves anti-cancer drug gemcitabine (GEM) sensitivity of p53-deficient human pancreatic cancer AsPC-1 cells through the augmentation of p53 family TAp63-dependent cell death pathway. In this manuscript, we have extended our study to p53-mutated human pancreatic cancer Panc-1 cells. According to our present results, knockdown of mutant p53 alone had a marginal effect on GEM-mediated cell death of Panc-1 cells. We then sought to deplete RUNX2 using siRNA in Panc-1 cells and examined its effect on GEM sensitivity. Under our experimental conditions, RUNX2 knockdown caused a significant enhancement of GEM sensitivity of Panc-1 cells. Notably, GEM-mediated induction of TAp63 but not of TAp73 was further stimulated in RUNX2-depleted Panc-1 cells, indicating that, like AsPC-1 cells, TAp63 might play a pivotal role in the regulation of GEM sensitivity of Panc-1 cells. Consistent with this notion, forced expression of TAp63α in Panc-1 cells promoted cell cycle arrest and/or cell death, and massively increased luciferase activities driven by TAp63-target gene promoters such as p21^WAF1 and NOXA. In addition, immunoprecipitation experiments indicated that RUNX2 forms a complex with TAp63 in Panc-1 cells. Taken together, our current observations strongly suggest that depletion of RUNX2 enhances the cytotoxic effect of GEM on p53-mutated Panc-1 cells through the stimulation of TAp63-dependent cell death pathway even in the presence of a large amount of pro-oncogenic mutant p53, and might provide an attractive strategy to treat pancreatic cancer patients with p53 mutations.

Extensive use of vasodilator agents and functional echocardiography to monitor extremely-low-birth-weight infants in Japan

National surveys were conducted in Japan to assess the current practices for circulatory management of extremely-low-birth-weight infants (ELBWIs) in acute phases. Approximately 80 and 100 institutions were surveyed in 2006 and 2011, respectively. Echocardiography was identified as an important diagnostic tool at 95% of the surveyed institutions. Furthermore, 74% of the institutions survey in 2011 used vasodilator agents. In 2011, the mean velocity of circumferential fiber shortening (mVcfc) and left ventricular end-systolic wall stress (ESWS) were used by 60% of the surveyed institutions to evaluate the relationship between afterload of the left ventricle and left ventricular contractility. Overall, the data collected from these national surveys clarified the current practices for circulatory management of ELBWIs in Japan, particularly the use of echocardiography and cardiovascular agents, including catecholamines and vasodilators.

Depletion of runt-related transcription factor 2 (RUNX2) enhances SAHA sensitivity of p53-mutated pancreatic cancer cells through the regulation of mutant p53 and TAp63

Suberoylanilide hydroxamic acid (SAHA) represents one of the new class of anti-cancer drugs. However, multiple lines of clinical evidence indicate that SAHA might be sometimes ineffective on certain solid tumors including pancreatic cancer. In this study, we have found for the first time that RUNX2/mutant p53/TAp63-regulatory axis has a pivotal role in the determination of SAHA sensitivity of p53-mutated pancreatic cancer MiaPaCa-2 cells. According to our present results, MiaPaCa-2 cells responded poorly to SAHA. Forced depletion of mutant p53 stimulated SAHA-mediated cell death of MiaPaCa-2 cells, which was accomapanied by a further accumulation of γH2AX and cleaved PARP. Under these experimental conditions, pro-oncogenic RUNX2 was strongly down-regulated in mutant p53-depleted MiaPaCa-2 cells. Surprisingly, RUNX2 silencing augmented SAHA-dependent cell death of MiaPaCa-2 cells and caused a significant reduction of mutant p53. Consistent with these observations, overexpression of RUNX2 in MiaPaCa-2 cells restored SAHA-mediated decrease in cell viability and increased the amount of mutant p53. Thus, it is suggestive that there exists a positive auto-regulatory loop between RUNX2 and mutant p53, which might amplify their pro-oncogenic signals. Intriguingly, knockdown of mutant p53 or RUNX2 potentiated SAHA-induced up-regulation of TAp63. Indeed, SAHA-stimulated cell death of MiaPaCa-2 cells was partially attenuated by p63 depletion. Collectively, our present observations strongly suggest that RUNX2/mutant p53/TAp63-regulatory axis is one of the key determinants of SAHA sensitivity of p53-mutated pancreatic cancer cells.

Abstract 3775: Mutated cancer cell-specific cell death activity of alkylating Pyrrole-Imidazole polyamide conjugates targeting a variety of oncogenic driver gene mutations

Cancer may be recognized as non-self by antibiotics such as minor groove binders, which show self / non-self recognition partially due to preferential DNA sequence recognition and distinguish from other non-self bacteria. We learned minor groove binders produced from Streptomyces and synthesized Pyrrole-Imidazole polyamide indol-seco CBI conjugate to alkylate specific sites in the cancer genome.

Although a tremendous amount of studies has been made to directly target oncogenic drivers, such as RAS and MYC, yet no drug is clinically available because of difficulties to develop RAS- or Myc-targeted anti-cancer therapeutics due to the smooth 3D surface topology. One of major limitations of targeting the RAS pathway may be intrinsic or acquired resistance as seen in the other molecular target therapy. New approaches that directly target driver genes may provide a more direct route to helps address unmet medical needs for refractory cancer conquest.

We therefore synthesized several Pyrrole-Imidazole polyamide conjugates, each of which specifically alkylated KRAS codon 12 mutant DNA (G12D or G12V), amplified MYCN or mutated DNA of PI3K E542K mutation. All three conjugates reduced expression of the mutated oncogenic-protein by RNA transcription inhibition and induced cancer cell death at low dose (1 to 50 nM). Low dose tail vein injections of conjugates-targeting KRS or MYCN also demonstrated significant anti-tumor effects on xenograft models of human tumors harboring oncogenic mutated driver with minimum host toxicity, but not in xenografts harboring wild type or non-recognized mutations. We also performed a series of biological searches for toxicities by applying Modified SHIRPA (behavioral and functional analysis of mouse phenotype) to test any pathological phenotypes and examinations of blood and urine in ICR mice. Modified SHIRPA screening, blood chemistry, blood cell analysis and urea tests exhibited no toxicologically significant changes. Additionally, we examine pharmacokinetics of PI polyamide conjugates In vivo using LC-mass and fluorescent imaging of tumor-bearing mice. Intriguingly, 48 hours after the administration the highest fluorescence intensity was observed in the tumor-cell nuclear and almost no fluorescent intensity in all other organs, tissues and cells. These data suggest that sequence-dependent alkylating approach using antibiotic mimics of alkylating PI-polyamide conjugates, may open a new strategy not only targeting point mutation of driver oncogene but also targeting key driver gene in the cancer amplicon. This approach should be used for future ‘ Precision cancer medicine’.

Citation Format: Hiroki Nagase, Kiriko Hiraoka, Takahiro Inoue, Hiroyuki Yoda, Krishnamurthy Sakthisri, Jason Lin, Takayoshi Watanabe, Nobuko Koshikawa, Atsushi Takatori. Mutated cancer cell-specific cell death activity of alkylating Pyrrole-Imidazole polyamide conjugates targeting a variety of oncogenic driver gene mutations. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3775.

Improvement of gemcitabine sensitivity of p53-mutated pancreatic cancer MiaPaCa-2 cells by RUNX2 depletion-mediated augmentation of TAp73-dependent cell death

Pancreatic cancer exhibits the worst prognostic outcome among human cancers. Recently, we have described that depletion of RUNX2 enhances gemcitabine (GEM) sensitivity of p53-deficient pancreatic cancer AsPC-1 cells through the activation of TAp63-mediated cell death pathway. These findings raised a question whether RUNX2 silencing could also improve GEM efficacy on pancreatic cancer cells bearing p53 mutation. In the present study, we have extended our study to p53-mutated pancreatic cancer MiaPaCa-2 cells. Based on our current results, MiaPaCa-2 cells were much more resistant to GEM as compared with p53-proficient pancreatic cancer SW1990 cells, and there existed a clear inverse relationship between the expression levels of TAp73 and RUNX2 in response to GEM. Forced expression of TAp73α in MiaPaCa-2 cells significantly promoted cell cycle arrest and/or cell death, indicating that a large amount of TAp73 might induce cell death even in the presence of mutant p53. Consistent with this notion, overexpression of TAp73α stimulated luciferase activity driven by p53/TAp73-target gene promoters in MiaPaCa-2 cells. Similar to AsPC-1 cells, small interfering RNA-mediated knockdown of RUNX2 remarkably enhanced GEM sensitivity of MiPaCa-2 cells. Under our experimental conditions, TAp73 further accumulated in RUNX2-depleted MiaPaCa-2 cells exposed to GEM relative to GEM-treated non-silencing control cells. As expected, silencing of p73 reduced GEM sensitivity of MiPaCa-2 cells. Moreover, GEM-mediated Tyr phosphorylation level of TAp73 was much more elevated in RUNX2-depleted MiaPaCa-2 cells. Collectively, our present findings strongly suggest that knockdown of RUNX2 contributes to a prominent enhancement of GEM sensitivity of p53-mutated pancreatic cancer cells through the activation of TAp73-mediated cell death pathway, and also provides a promising strategy for the treatment of patients with pancreatic cancer bearing p53 mutation.

Abstract 4691: KRAS mutation specific alkylating pyrrole-imidazole polyamide (KR12) suppresses mutant KRAS expression and inhibits tumor growth by showing accumulation in KRAS mutant xenografts

Constitutive active mutations of KRAS are detected in 35-40% of human colon cancers, and almost all of them are the constitutive active missense mutations at codon 12 (80%) or codon 13 (20%). Consistent with these observations, the presence of KRAS mutations has been shown to be associated with malignant properties of tumors as well as a poor clinical outcome of the patients bearing these tumors. Unfortunately, yet no effective anti-cancer drug(s) specifically targeting KRAS mutations have been developed. Hence, we synthesized an alkylating agent conjugated with the Pyrrole-Imidazole polyamide (KR12: PI-polyamide-seco-CBI), which recognized KRAS G12D or G12V mutations at codon12. We have previously found that KR12 has anti-tumor effects in vitro and in vivo. However, it still remains elusive whether KR12 exerts its selective toxicity towards colon cancer cells by penetrating into the tumor tissues and inhibiting the expression of mutant KRAS gene in mouse model of human cancer. To address this issue, we decided to examine the distribution of KR12 using FITC labeled PI polyamide. In vivo imaging of tumor-bearing mice after single intravenous administration demonstrated that the highest fluorescence intensity was seen in the tumor sites 24 hours after injection with showing nuclear localization. Quantitative RT-PCR revealed that KR12 decreased the mutated KRAS expression in tumor tissues obtained from KRAS-heterozygous-mutated-LS180-xenografted mice (G12D heterozygous mutation). Since KR12 showed long lasting accumulation in xenografts we compared the effect of single and multiple administration of KR12. Once a week injection for five to eight weeks resulted in significant suppression of tumor growth in homozygous mutant SW480 (G12V homozygous mutation) xenografts. Surprisingly, both single and multiple treatments of KR12 induced massive tumor volume reduction without affecting body weight gain. These data suggest that KR12 accumulation in colon xenograft tumor tissues may emphasize drug local effect and minimize systemic adverse effect.

Citation Format: Takahiro Inoue, Kiriko Hiraoka, Yusei Suzuki, Hiroyuki Yoda, Takayoshi Watanabe, Atsushi Takatori, Nobuko Koshikawa, Toshinori Ozaki, Hiroki Nagase. KRAS mutation specific alkylating pyrrole-imidazole polyamide (KR12) suppresses mutant KRAS expression and inhibits tumor growth by showing accumulation in KRAS mutant xenografts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4691. doi:10.1158/1538-7445.AM2015-4691

Abstract 4687: A novel alkylating pyrrol-imidazole polyamide, KR12, specifically recognizes mutant KRAS genes and potently induces cell death

RAS mutations are found in around 30% of all human cancers, with KRAS being the most frequently activated RAS family of oncogenes. Although extensive efforts to develop attractive chemotherapeutic drugs targeting KRAS mutations with clinical benefit have been made, these experimental trials have often resulted in unsuccessful. Recently, we have successfully produced for the first time a novel alkylating agent (termed KR12) conjugated with the sequence-specific Pyrrole-Imidazole polyamide (PI polyamide), which was expected to have an ability to bind to base sequences of KRAS mutations at codon 12 (G12D and G12V). According to our results, KR12-treated colon cancer-derived LS180 cells carrying a KRAS G12D heterozygous mutation underwent remarkable G2/M cell cycle arrest, cellular senescence and subsequent p53-dependent apoptotic cell death in association with a massive down-regulation of mutant KRAS expression as examined by quantitative real-time RT-PCR and immunoblotting. In the present study, we have further assessed the sequence-specificity of KR12 in detail by using an in vitro gel mobility shift assay, binding affinity assays with surface plasmon resonance (Biacore system) and also determined IC50 of KR12 in a variety of colon cancer-derived cells with the distinct KRAS status. Gel mobility shift assay demonstrated that the mobility of the oligonucleotide containing KRAS mutation was significantly retarded in the presence of KR12 but not in the absence of KR12. In agreement, KR12 specifically bound to the oligonucleotide containing KRAS mutation with high affinity as examined by Biacore system in vitro. Notably, ligation-mediated PCR analysis (LM-PCR) revealed that KR12 indeed alkylate the adenine residue next to KRAS at codon G12D in LS180 cells. These observations imply that KR12 is capable to bind to and alkylate the expected KRAS sequence in vitro and in cells. Next, we have investigated the sensitivity to KR12 in a variety of colon cancer-derived cells. Based on our standard WST cell survival assay demonstrated that KRAS mutation-bearing SW480 (G12V), SW620 (G12V), and LS180 (G12D) cells exhibited a significantly higher sensitivity to KR12 as compared with HT-29 (WT), Caco-2 (WT), DLD-1 (G13D) and SW1463 (G12C) cells. Taken together, our present results strongly suggest that KR12 is a novel sequence-specific alkylating agent targeting KRAS G12D as well as G12V mutation, and thus might be a promising anti-cancer drug for the treatment of patients bearing malignant cancers with KRAS mutations.

Citation Format: Kiriko Hiraoka, Takahiro Inoue, Hiroyuki Yoda, Atsushi Takatori, Takayoshi Watanabe, Nobuko Koshikawa, Toshinori Ozaki, Hiroki Nagase. A novel alkylating pyrrol-imidazole polyamide, KR12, specifically recognizes mutant KRAS genes and potently induces cell death. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4687. doi:10.1158/1538-7445.AM2015-4687

Runt-related transcription factor 2 attenuates the transcriptional activity as well as DNA damage-mediated induction of pro-apoptotic TAp73 to regulate chemosensitivity

Although runt-related transcription factor 2 (RUNX2) is known to be an essential key transcription factor for osteoblast differentiation and bone formation, RUNX2 also plays a pivotal role in the regulation of p53-dependent DNA damage response. In the present study, we report that, in addition to p53, RUNX2 downregulates pro-apoptotic TAp73 during DNA damage-dependent cell death. Upon adriamycin (ADR) exposure, human osteosarcoma-derived U2OS cells underwent cell death in association with an upregulation of TAp73 and various p53/TAp73-target gene products together with RUNX2. Small interfering RNA-mediated silencing of p73 resulted in a marked reduction in ADR-induced p53/TAp73-target gene expression, suggesting that TAp73 is responsible for the ADR-dependent DNA damage response. Immunoprecipitation and transient transfection experiments demonstrated that RUNX2 forms a complex with TAp73 and impairs its transcriptional activity. Notably, knockdown of RUNX2 stimulated ADR-induced cell death accompanied by a massive induction of TAp73 expression, indicating that RUNX2 downregulates TAp73 expression. Consistent with this notion, the overexpression of RUNX2 suppressed ADR-dependent cell death, which was associated with a remarkable downregulation of TAp73 and p53/TAp73-target gene expression. Collectively, our present findings strongly suggest that RUNX2 attenuates the transcriptional activity and ADR-mediated induction of TAp73, and may provide novel insights into understanding the molecular basis behind the development and/or maintenance of chemoresistance. Thus, we propose that the silencing of RUNX2 might be an attractive strategy for improving the chemosensitivity of malignant cancers.

[Primary arterial switch operation for complete transposition of the great arteries (type I) of a neonate weighing 1,378 g]

A 2-day-old female baby, delivered by emergent cesarean section at 35 weeks of gestational age with a birth weight of 1,378 g, was referred to our institute for intensive care of heart failure. By echocardiography and cardiac catheterization, the patient was diagnosed with isolated complete transposition of the great arteries. Primary arterial switch operation was performed at 13 days of age. No technical difficulty arose, imposed by the small size of cardiovascular structure. On the 5th postoperative day, surgical repair of intestinal perforation was performed. Convalescence thereafter was uneventful. She returned home on the 64th postoperative day with the body weight of 2,310 g. We conclude that primary arterial switch operation can be a feasible surgical option even in a neonate with very low birth weight.

Congenital pulmonary-systemic collateral vein without obstructed left atrial egress is associated with conotruncal anomalies

We present a case of congenital pulmonary systemic collateral vein associated with truncus arteriosus. Pulmonary systemic collateral vein with nonobstructed left atrial egress is different from those with obstructed left atrial egress in that it is functionally redundant. Including this case, 8 patients among 33 reported cases with pulmonary systemic collateral veins have had nonobstructed left atrial egress. Association with conotruncal anomalies in 4 of these 8 patients, as well as the reported finding that neural crest cells are distributed not only in the conotruncus but also in the cardinal vein, indicates that neural crest cells play roles in remodeling of the systemic venous system.

Identification of early-responsive genes associated with the hypersensitive response to tobacco mosaic virus and characterization of a WRKY-type transcription factor in tobacco plants

In order to identify genes that are involved in the defense reaction against pathogen attack, we screened for examples that are regulated during the hypersensitive response (HR) to infection by tobacco mosaic virus (TMV) of tobacco ( Nicotiana tabacum cv. Xanthi nc) carrying the N gene, which confers resistance to TMV. Among seven genes initially identified by fluorescent differential display, one clone was further characterized because its transcripts accumulated rapidly and transiently after the onset of HR. Its full-length cDNA of 1346 bp encoded a polypeptide consisting of 258 amino acids. The deduced protein contained a single WRKY domain, a Cys(2)His(2) zinc-finger motif and a leucine-zipper motif, showing high similarity to WIZZ, a member of the family of WRKY transcription factors in tobacco. The gene was thus designated TIZZ. A GFP-TIZZ fusion protein was found to localize to the nucleus upon introduction into epidermal cells of onion. Bacterially expressed TIZZ was able to bind to the W-box (TTGAC) element that is recognized by other WRKY proteins, but transactivation assays showed it to be unable to activate reporter gene expression by itself. TIZZ transcripts were induced in TMV-infected nahG transgenic tobacco plants, in which salicylic acid fails to accumulate. Neither exogenously applied salicylic acid nor mechanical wounding induced TIZZ transcript accumulation. These results indicate the presence of salicylic acid-independent pathways for HR signal transduction, in which a novel type of WRKY protein(s) may play a critical role for the activation of defense.

[A case of Down syndrome with ventricular septal defect and hemodynamical Eisenmenger syndrome]

A 10 month-old infant with Down syndrome having ventricular septal defect and pulmonary hypertension performed cardiac catheterization, which resulted in a slight increase in the pulmonary vascular resistance from 10.8 to 11.3 unit.m2. Lung biopsy findings showed at most an early grade 2 Heath-Edwards classification, and an index of pulmonary vascular disease of 1.1, both of which indicated operability for total correction. He underwent surgical correction and the pulmonary arterial pressure significantly decrease. Although he suffered chylothorax in 5th postoperative day, he did not developed pulmonary hypertension crisis.

Clinicopathological analysis of premature infants treated with artificial surfactant

OBJECTIVE

Our aim was to obtain new information about the relationship between infant responses to surfactant replacement therapy and histopathological changes in vital organs.

STUDY DESIGN

To accomplish this, the autopsy findings and clinical backgrounds of 41 very low birth weight infants (gestational week 25.6 +/- 2.3; birth weight 806.4 +/- 251.6g) who had died after receiving surfactant replacement therapy were reviewed, and those who responded to therapy were compared with those who did not. Responders were infants in whom the required FiO(2) declined by > 20% or mean airway pressure declined by > 20% within six hours of instilling surfactant (n=18); non-responders were infants who did not meet those criteria (n=23).

RESULT

Gestational age, birth weight and time at treatment were similar in responders and non-responders, but survival was significantly longer in responders. The incidences of hyaline membrane disease, pulmonary interstitial emphysema, hemorrhagic necrosis and parenchymal degeneration of the liver and kidney were all higher in non-responders, whereas the incidences of bronchopulmonary dysplasia and pneumonia were higher in responders. Prior to treatment, acidosis and hypothermia were significantly more severe in non-responders, and perinatal complications, such as fetal distress and intrauterine infection, were observed more often in non-responders. Substantial degradation of vital organs had already occurred during the early post-natal or intrauterine life of the non-responders, which would be expected to interfere with the clinical response to instilled surfactant.

CONCLUSION

It is anticipated that in the future improved monitoring of immature fetuses will be indispensable to improve intrauterine fetal management and to achieve better control over the timing and mode of delivery.

Zebrafish mutations in Gli-mediated hedgehog signaling lead to lens transdifferentiation from the adenohypophysis anlage

It is known that the earliest lens marker delta-crystallin is expressed abundantly in Rathke's pouch of the chicken, suggesting a close relationship between the cell states of the adenohypophysis (pituitary) anlage and the early lens. We show here that the zebrafish midline mutants you-too (yot) and iguana (igu) develop lenses from the adenohypophysis anlage. The early adenohypophysis anlage of normal zebrafish expresses lim3 and six3 but in yot(ty119) mutants the anterior part of the anlage lacks lim3 expression, and instead produces a crystallin-expressing cell population which develops into a large lens structure expressing beta and gamma-crystallins, but is not associated with retina tissues. Among the zebrafish mutants with midline defects, midline lenses were observed in two mutant alleles of yot and an allele of igu, but not in other mutants (syu, con, smh, dtr, uml, spi and lok). Two yot mutant alleles with midline lenses likely encode dominant negative forms of the Gli2 protein which will interfere with transcriptional activation by other Gli proteins. The observation argues that overall inhibition of Shh-Gli signaling leads the adenohypophysis anlage to transdifferentiate into lens.

Loss of cadherin-11 adhesion receptor enhances plastic changes in hippocampal synapses and modifies behavioral responses

Cadherins organize symmetrical junctions between the pre- and postsynaptic membranes in central synapses. One of them, cadherin-11 (cad11), is expressed in the limbic system of the brain, most strongly in the hippocampus. Immunohistochemical studies of the hippocampus showed that cad11 proteins were densely distributed in its synaptic neuropil zones; in cultured hippocampal neurons, their distribution often overlapped with that of synaptophysin, and also occasionally with that of GluR1 at spines. To assess the role of cad11 in synaptic formation and/or function, we analyzed brains of cad11-deficient mice. In these mice, long-term potentiation (LTP) in the CA1 region of the hippocampus was, unexpectedly, enhanced; and the level of LTP saturation was increased. In behavioral tests, the mutant mice showed reduced fear- or anxiety-related responses. These results suggest that the cad11-mediated junctions may modulate synaptic efficacy, confining its dynamic changes to a limited range, or these junctions are required for normal development of synaptic organization in the hippocampus.

Expressed sequence tags from immature female sexual organ of a liverwort, Marchantia polymorpha

A total of 970 expressed sequence tag (EST) clones were generated from immature female sexual organ of a liverwort, Marchantia polymorpha. The 376 ESTs resulted in 123 redundant groups, thus the total number of unique sequences in the EST set was 717. Database search by BLAST algorithm showed that 302 of the unique sequences shared significant similarities to known nucleotide or amino acid sequences. Six unique sequences showed significant similarities to genes that are involved in flower development and sexual reproduction, such as cynarase, fimbriata-associated protein and S-receptor kinase genes. The remaining unique 415 sequences have no significant similarity with any database-registered genes or proteins. The redundant 123 ESTs implied the presence of gene families and abundant transcripts of unknown identity. Analyses of the coding sequences of 61 unique sequences, which contained no ambiguous bases in the predicted coding regions, highly homologous to known sequences at the amino acid level with a similarity score greater than 400, and with stop codons at similar positions as their possible orthologues, indicated the presence of biased codon usage and higher GC content within the coding sequences (50.4%) than that within 3' flanking sequences (41.9%).

AFP-producing squamous cell carcinoma of the lung in an adolescent

We report a case of primary lung cancer in a 16-year-old boy. A histologic diagnosis of squamous cell carcinoma was made by bronchoscopic biopsy before surgery. The serum alphafetoprotein (AFP) level was markedly elevated at 193 ng/dl. Preoperative and postoperative evaluation revealed no evidence of scrotal mass. We performed right pneumonectomy with combined resection of the invaded portion of the left atrium under extracorporeal circulation. Despite the rapid improvement in the patient's general condition after surgery, the AFP level continued to increase without a transient decrease and reached 3160 ng/ml on the 23rd postoperative day. When the patient was readmitted because of dyspnea and headache on the 36th postoperative day, hypercalcemia of 13.9 mg/dl was noted, and this was resistant to subsequent treatment. The patient died on the 46th postoperative day.

Blood flow velocities in the cerebral arteries and descending aorta in small-for-dates infants

Resistive indices (RI) in the anterior cerebral artery (ACA), basilar artery (BA), middle cerebral artery (MCA) and descending aorta (DA) were obtained in 15 small-for-dates (SFD) infants who were, growth retarded because of maternal pregnancy-induced hypertension and in 20 appropriate-for-dates (AFD) infants matched for gestational age between 24 h and 48 h after birth. The RIs in the MCA, ACA and BA were significantly lower, while the RI in the DA was significantly higher, in the SFD infants than in the AFD infants. These changes in RIs in the SFD infants might be similar to the "brain sparing" effect as reported in growth-retarded fetuses.

[Incidence and causes of neonatal seizures in the last 10 years (1981-1990)]

We report the incidence of neonatal seizures in the last 10 years. Between 1981-1990, 28,925 infants were born in the Japanese Red Cross Medical Center. Very low-birth-weight infants (< 1,500 g) were excluded in this study. Seizures were identified in 67 infants (0.23%) during the first 7 days of life. Seizures occurred more frequently in low-birth-weight infants (1,500-2,499 g) than in normal-birth-weight infants (> 2,499 g). Fifty-one infants (0.19%) of 27,276 normal-birth-weight infants and 16 (0.97%) of 1,649 low-birth-weight infants developed seizures. The frequency of seizures was 0.25% during the first 5 years and 0.20% during the second 5 years. In low-birth-weight group, the frequency of seizures decreased form 1.49% to 0.48% during the 5-year periods, and seizures due to post asphyxial hypoxic-ischemic encephalopathy also decreased from 0.14% to 0.06%. The decreased incidence in neonatal seizures during the last 10 years was probably achieved by the progress in intervention of low-birth-weight infants in NICU and by the obstetrical prevention of intrapartum asphyxia.

Development of hepatocellular carcinoma in a man with auto-immune chronic active hepatitis

A 57 year old man with auto-immune chronic active hepatitis, regularly treated with immunosuppressive therapy, had hepatocellular carcinoma (HCC) 10 years after diagnosis of the hepatitis. Assays of the hepatitis C virus antibodies against capsid and non-structural proteins revealed seronegativity in serial serum samples of this patient stored in the previous 10 years during follow up. The seronegative hepatitis C antibodies excluded hepatitis C virus as the cause of the HCC. The occurrence of HCC in this case suggests the necessity of surveillance for early detection of liver cancer in patients with auto-immune chronic active hepatitis undergoing long-term immunosuppressive therapy.

[Clinical evaluation of imipenem/cilastatin sodium against severe infections complicating hematological disorders and solid tumors]

Imipenem/cilastatin sodium (IPM/CS) was administered to a total of 67 patients with severe infections complicating hematological disorders and solid tumors. Fifty patients are included in the present analysis of efficacy and 64 in that of safety. 1. Out of 31 patients with hematological disorders, responses were excellent in 10 patients, good in 10 patients, and the efficacy rate was 64.5%. Out of 19 patients with solid tumors, responses were excellent in 8 patients, good in 8 patients and the efficacy rate was 84.2%. 2. For patients whose responses to other antibiotics had been poor, the efficacy rate was 59.3% in the group with hematological disorders and 62.5% in the group with solid tumors. 3. The relationship between the neutrophil count and efficacy was studied in the patients with hematological disorders. The efficacy rate for 8 patients whose neutrophil counts were 500/mm3 or less was 75.0%. 4. For the patients with hematological disorders, the efficacy rate for patients from whom causative organisms were isolated was 70.0% and that for patients for whom they were unknown was 61.9%. 5. Adverse reactions were observed in 3 patients and abnormal laboratory test results in 2 patients. However, they were mild and disappeared after discontinuation of this drug. From these results, IPM/CS is considered to be a useful antibiotic for the treatment of severe infections complicating hematological disorders and solid tumors.

A case of Caroli's disease with hepatolithiasis, choledocholithiasis, and cholangiocarcinoma

A 48-year-old woman with Caroli's disease accompanied by hepatolithiasis, choledocholithiasis, and cholangiocarcinoma is reported. Magnetic resonance imaging was useful for the diagnosis of the cholangiocarcinoma. The relationship between cholangiocarcinoma and hepatolithiasis, choledocholithiasis, and chronic cholangitis in Caroli's disease is discussed.

Cerebral blood flow velocities in the anterior cerebral arteries and basilar artery in hydrocephalus before and after treatment

We studied Pourcelot's index (PI), which shows cerebral vascular resistance, in the anterior cerebral arteries and basilar artery, and the PI ratio (Pourcelot's index in the anterior cerebral artery/Pourcelot's index in the basilar artery) in 11 measurements of hydrocephalus. The mean values of PI in the anterior cerebral artery, basilar artery, and the PI ratio before treatment were significantly higher than those after treatment and those in normal infants. Before treatment, the mean PI in the anterior cerebral arteries was significantly higher than the mean PI in the basilar artery. All PI ratios increased to 1.00 or more. After treatment and in normal infants, the mean PI in the anterior cerebral arteries was significantly lower than the mean PI in the basilar artery. All PI ratios decreased to less than 1.00. We believe that the PI ratio is useful to evaluate the need or effect of treatment in hydrocephalus.

A case of Dandy-Walker malformation associated with occipital meningocele, microphthalmia, and cleft palate

We present a case of Dandy-Walker malformation associated with occipital meningocele, microphthalmia, and cleft palate. Small numbers of cases of Dandy-Walker malformation with occipital meningocele have been described in the literature, but to our knowledge, non of these also had microphthalmia or cleft palate. This association suggests that time of intrauterine origin of Dandy-Walker syndrome was in the sixth or seventh embryonic week. In the diagnosis, both CT cisternography and direct neurosonography over the occipital meningocele was useful for the demonstration of a posterior fossa cyst which communicated with the fourth ventricle and the occipital meningocele.

Treatment of chronic non-A non-B hepatitis with human interferon beta: a preliminary study

Twenty-four patients with chronic non-A non-B hepatitis were randomly assigned to receive either human fibroblast interferon (HuIFN-beta) at doses of 1 or 3 million international units (MIU) per day for 4 or 12 weeks (12 patients) or to receive no therapy (12 patients), and were then compared with 5 patients with chronic type B hepatitis who were treated with HuIFN-beta. Elevated serum aminotransferase levels decreased more rapidly during the treatment of chronic non-A non-B hepatitis than of chronic hepatitis B. Variations in serum aminotransferases were not observed in any of the untreated chronic non-A non-B hepatitis patients. In 3 of the 9 patients with chronic non-A non-B hepatitis who responded to HuIFN-beta therapy, serum aminotransferase levels remained normal 15, 21 and 31 months after therapy was discontinued; liver biopsy specimens obtained after therapy from 2 patients showed marked histological improvement. In the six other patients aminotransferase activity levels became again elevated following cessation of interferon therapy. No response to HuIFN-beta was seen in the remaining 3 patients with chronic non-A non-B hepatitis.

Serial assay for IGM anti-HBc in patients with anti-HBe-positive chronic hepatitis and its significance for long-term prognosis

Serial assays for immunoglobulin M antibody to hepatitis B core antigen (IgM anti-HBc) were performed in 51 patients with antibody to hepatitis B e antigen (anti-HBe) in their sera. IgM anti-HBc was detected periodically and persistently in 8 (53%) of 15 patients with chronic hepatitis whose serum glutamic pyruvic transaminase (GPT) levels were elevated and was not detected in 36 patients with normal serum GPT levels. Antibody to delta agent was not detected in any of the patients. Of the eight patients positive for IgM anti-HBc, four had a high titer of IgM anti-HBc and either developed liver cirrhosis (three cases) or died due to massive hepatic necrosis (one case); the other four showed a low level of IgM anti-HBc and either recovered (two cases) or developed chronic persistent hepatitis (two cases). Of seven patients negative for IgM anti-Hbc, two had a fatty liver, and five, who had a history of blood transfusion, had chronic hepatitis. Thus, even though anti-HBe may be present, if the titer of IgM anti-HBc is high, the histological activity can be expected to increase, and the prognosis will be poor. If the titer of IgM anti-HBc is low, the histological activity may be expected to decrease, and the prognosis may be good. In patients with abnormally high serum GPT but without IgM anti-HBc, another type of hepatitis or a secondary form of liver disease should be considered.

Possible infectious causes in 651 patients with acute viral hepatitis during a 10-year period (1976-1985)

Six hundred and fifty-one patients with acute viral hepatitis were identified serologically between January 1976 and December 1985. Of these, 109 (17%) had hepatitis A, 135 (21%) had hepatitis B, and 407 (62%) had hepatitis non-A, non-B. The possible infectious causes for acquisition of viral hepatitis occurring within 6 months before the onset of hepatitis were analysed. Approximately 80% of cases of hepatitis A and 70% of hepatitis B had no known risk factor, while in 67% of cases of hepatitis non-A, non-B possible risk factors for infection were documented. Infectious causes for hepatitis A were ingestion of raw shellfish (11%) and previous familial contact with patients with hepatitis A (10%). For hepatitis B, risk factors included medicare (24%), such as transfusion, surgical operation, accidental needle stick and acupuncture, and sexual contact (6%). For hepatitis non-A, non-B, the most important infectious cause was medical procedures (65%). The numbers of hospital employees were 2 (2%) with hepatitis A, 15 (11%) with hepatitis B and 14 (3%) with hepatitis non-A, non-B. These data suggest that hepatitis non-A, non-B can be a kind of nosocomial disease.

Significance of IgM antibody to hepatitis B core antigen for the differential diagnosis of acute and chronic hepatitis B virus infection and for the evaluation of the inflammatory activity of type B chronic liver diseases

IgM antibody to hepatitis B core antigen (anti-HBc) was assayed using a commercial kit in acute and chronic hepatitis B virus (HBV) infection and evaluated for its diagnostic and clinical significance. IgM anti-HBc was positive in all of 21 cases with type B acute hepatitis in the acute phase, and was also detected in 5 of 20 cases with type B chronic persistent hepatitis, in 4 of 20 patients with type B chronic active hepatitis and in one of 10 with type B liver cirrhosis. The absence of this marker was noted in all of 20 asymptomatic hepatitis B surface antigen (HBsAg) carriers and in 50 with HBsAg-negative patients with liver disease and in 200 healthy blood donors. The cut-off index of IgM anti-HBc was greater than 2.0 in all serum samples obtained in the acute phase of type B acute hepatitis, but was below 2.0 in type B chronic liver disease. A close relationship was found between the presence of IgM anti-HBc and the degree of inflammatory activity in patients with HBsAg-positive chronic liver disease. These data show that examination of IgM anti-HBc is useful in distingushing type B acute hepatitis from type B chronic liver disease, and also in evaluating the severity of disease in type B chronic liver disease.

Evolution of HBeAg/anti-HBe status and its relationship to clinical and histological outcome in chronic HBV carriers in childhood

Fifty-five Japanese HBV carriers under 15 yr of age were followed for 12 months or longer, during which time we investigated the evolution of HBeAg/anti-HBe status and clinical and histological aspects of the liver disease. Of 45 cases positive for HBeAg at the initial examination, 34 remained positive for HBeAg during the follow-up periods, while the remaining 11 lost HBeAg and eight of these seroconverted to anti-HBe. At the final observation, HBeAg positivity in serum was found in as many as approximately 90% of the HBV carriers under 6 yr, but had fallen to 48% in carriers between 12 and 15 yr. The serum transaminase values in 11 cases who lost HBeAg were abnormally elevated for variable periods, but eventually returned to normal. In six of these 11 who had liver dysfunctions, liver biopsy was performed during the HBeAg positive phase or shortly after the disappearance of HBeAg. The histologies of liver were chronic persistent hepatitis in two cases and chronic active hepatitis in four. Repeat liver biopsies of two cases with chronic active hepatitis at the first examination showed nonspecific reactive hepatitis 2 and 4 yr after seroconversion or disappearance of HBeAg. These results indicate that HBeAg-positive HBV carriers with overt liver dysfunctions in childhood are prone to lose HBeAg or to seroconvert to anti-HBe, followed by a marked histological regression, and therefore that special antiviral therapy is probably unnecessary.

Experimental infection of Bordetella bronchiseptica to rabbits

Infectivity and pathogenicity of Bordetella bronchiseptica to rabbits were investigated by intranasal inoculation of the organism to suckling and young animals. Results are summarized as follows. 1. By inoculation of 5 X 10(4) and 10(6) organisms, the infection developed in 60% and 100% of young rabbits, respectively. 2. In young rabbits, the growth of the organism was evident in the trachea within 5 days after inoculation and in the lung on the 10th day. The organism began to disappear from the lung and trachea of some animals from the 40th day after inoculation, but remained in the external nares and nasal cavity of all animals even on the 90th day. Neither clinical sign nor pneumonic lesion was observed in any stages of the infection. 3. Pneumonic lesions and serous nasal secretion were found in all suckling rabbits by inoculation of 5 X 10(6) organisms, but no fatal case was detected.