Recurrent Spindle Cell Carcinoma Shows Features of Mesenchymal Stem Cells.

This study investigated a case of spindle cell carcinoma (SpCC) in tongue pathological lesions. The patient experienced a local recurrence and distant metastasis after surgical intervention. Although standard chemotherapy was administered, a granulomatous mass continued to develop. This aggressive growth led to survival of the tumor. Secondary debulking surgery was performed to improve the patient's quality of life at the request of the patient. Using a tissue sample derived from the secondary debulking surgery, we performed an analysis of the tumor's cell surface antigens, differentiation potential, metastatic ability, and inhibition potential by anticancer reagents. In vitro analysis revealed that the cell population grown under adherent culture conditions expressed the mesenchymal stem cell (MSC) markers CD73, CD90, and CD105. The cell line established from this SpCC contained colony-forming unit fibroblasts (CFU-Fs) and exhibited multipotent differentiation into several mesenchymal lineages, including bone, cartilage, and fat. The SpCC cells also displayed vigorous mobilization. These characteristics suggested that they had the differentiation potential of mesenchymal cells, especially MSCs, rather than that of epithelial cells. The surgical specimen analyzed in this study resisted the molecular target reagent cetuximab, which is an epidermal growth factor receptor inhibitor. This clinical insight revealed that chemotherapy-resistant SpCC cells have different characteristics compared to most other cancer cells, which are sensitive to cetuximab. Our cell death assay revealed that SpCC cell death was induced by the anticancer drug imatinib, which is known to inhibit protein tyrosine kinase activity of ABL, platelet-derived growth factor receptor α (PDGFRα), and KIT. Here, we report recurrent SpCC with characteristics of MSCs and potential for treatment with imatinib.

Combination of low-dose total skin electron beam therapy and subsequent localized skin electron beam therapy as a therapeutic option for advanced-stage mycosis fungoides.

Electron beam therapy (EBT) is an established treatment for mycosis fungoides (MF), but evidence for the use of EBT in advanced cutaneous conditions is limited, and optimal scheduling of the regimen for such conditions remains unclear. We report the case of a 44-year-old woman diagnosed with MF with widespread cutaneous lesions, including multiple huge tumours in the craniofacial area. Low-dose total skin (TS)EBT and subsequent localized skin (LS)EBT achieved striking improvements in eruptions. Oral etretinate was also administered during therapy. Our experience implies that combined TSEBT and LSEBT may be worth attempting when a patient presents with both widespread lesions and prominent tumours, even when the tumours are extremely large.

Acquired dermal melanocytosis of the face and extremities.

Acquired dermal melanocytosis (ADM) is a relatively rare, but well-described disease among adolescent to middle-aged East Asian women, particularly those of Japanese and Chinese descent. Clinically, ADM manifests as multiple punctate and greyish-brown pigmented areas 1-3 mm in diameter occurring on both sides of the forehead and zygomatic region. The subtype of ADM affecting the face and extremities is extremely rare even in East Asian women. We describe three patients with ADM of the face and extremities (ADMFE) and their characteristic clinical features. All patients were Japanese women, and showed multiple greyish-brown pigmentations on both nasal wings and on the extensor surface of the extremities. We found that the clinical features were strikingly uniform, and that a pigmented lesion on the nasal wing can be an important clue to distinguish ADMFE from other hyperpigmented diseases of the hands and feet. One patient was treated with Q-switched ruby laser with excellent outcome. Increased awareness of ADMFE can lead to earlier diagnosis and potential treatment.

Translational initiation regulated by ATM in dendritic cells development.

Ataxia telangiectasia mutated (ATM) protein has been implicated in multiple pathways such as DNA repair, cell cycle checkpoint, cell growth, development, and stem cell renewal. In this study, we demonstrate evidence that ATM is involved in granulocyte macrophage colony-stimulating factor (GM-CSF)-induced dendritic cell (DC) development from bone marrow (BM) cells. Inactivation of ATM protein results in decreased BM proliferation, leading to reduced DC development and their activity for T cell activation. Expression of Jak2, STAT5, and mTOR is suppressed in both wild-type and ATM-null BM prior to GM-CSF stimulation. Activation of those proteins is delayed and prolonged hypophosphorylation of 4EBP1 is observed in ATM-null BM when treated with GM-CSF, although Erk and p38 are similarly expressed and activated in both wild-type and ATM-null BM cell types. Akt is also suppressed in wild-type BM, and transduction of constitutively active Akt or STAT5 in ATM-null BM restores DC development. Together, these results illustrate that ATM deficiency causes impaired initiation of protein translation in BM, leading to immature development of DC.

DNA damage induces reactive oxygen species generation through the H2AX-Nox1/Rac1 pathway.

The DNA damage response (DDR) cascade and ROS (reactive oxygen species) signaling are both involved in the induction of cell death after DNA damage, but a mechanistic link between these two pathways has not been clearly elucidated. This study demonstrates that ROS induction after treatment of cells with neocarzinostatin (NCS), an ionizing radiation mimetic, is at least partly mediated by increasing histone H2AX. Increased levels of ROS and cell death induced by H2AX overexpression alone or DNA damage leading to H2AX accumulation are reduced by treating cells with the antioxidant N-Acetyl-L-Cysteine (NAC), the NADP(H) oxidase (Nox) inhibitor DPI, expression of Rac1N17, and knockdown of Nox1, but not Nox4, indicating that induction of ROS by H2AX is mediated through Nox1 and Rac1 GTPase. H2AX increases Nox1 activity partly by reducing the interaction between a Nox1 activator NOXA1 and its inhibitor 14-3-3zeta. These results point to a novel role of histone H2AX that regulates Nox1-mediated ROS generation after DNA damage.

Phosphorylation of SMC1 by ATR is required for desferrioxamine (DFO)-induced apoptosis.

DNA damage signaling pathways are initiated in response to chemical reagents and radiation damage, as well as in response to hypoxia. It is implicated that structural maintenance of chromosomes 1 (SMC1) is not only a component of the cohesion complex but also facilitates the activation of DNA damage checkpoint proteins. Here, we studied the mechanism of DNA damage checkpoint activated by ATR-SMC1 pathway when cells are treated with desferrioxamine (DFO), a hypoxia-mimetic reagent. We show that DFO treatment induces phosphorylation of SMC1 at Ser966, NBS1 at Ser343, Chk1 at Ser317, Chk2 at Thr68, and p53 at Ser15. Among these sites, phosphorylation of SMC1, NBS1, and Chk1 by DFO are mediated by ATR as it is greatly reduced in both ATR-deficient human fibroblasts and HCT116 human colon cancer cells in which ATR is heterozygously mutated, whereas these proteins are phosphorylated in cells deficient for ATM and DNA-PKcs. DFO-induced apoptosis is decreased in ATR-mutant HCT116 cells, although p53 is normally activated in those cells. Expression of SMC1 S966A in which Ser966 is substituted to Ala attenuates apoptosis and phosphorylation of Chk1 at Ser317 after DFO treatment, although levels of HIF1α are not significantly changed. These results suggest that DFO induces apoptosis through the ATR-SMC1 arm of the pathway.

Indeterminate cell histiocytosis successfully treated with ultraviolet B phototherapy.

Indeterminate cell histiocytosis (ICH) is a rare disorder, characterized by infiltration of the skin by neoplastic cells that are characteristically positive for S-100 and CD1a, but lack Birbeck's granules. A 75-year-old man presented with a 4-year history of multiple papules on the trunk, limbs, face and neck. Skin biopsy revealed dense infiltration of histiocytic cells that were CD1a+/S100+, but lacked Birbeck's granules. No other abnormality was seen during a general examination including a computed tomography scan of the body, gallium scintigraphy, and an abdominal sonography. Broadband ultraviolet B (UVB) treatment was used for the skin lesions, and partial but almost complete remission was obtained. The case suggests that UVB phototherapy is an option for treatment of ICH.

Overexpression of aurora kinase A in mouse mammary epithelium induces genetic instability preceding mammary tumor formation.

Aurora-A/STK15/BTAK, which encodes a centrosome-associated kinase, is amplified and overexpressed in multiple types of human tumors, including breast cancer. However, the causal relationship between overexpression of Aurora-A and tumorigenesis has not been fully established due to contradictory data obtained from different experimental systems. To investigate this, we generated a mouse strain that carries an MMTV-Aurora-A transgene. We showed that all the MMTV-Aurora-A mice displayed enhanced branch morphogenesis in the mammary gland and about 40% developed mammary tumors at 20 months of age. The tumor incidence was significantly increased in a p53(+/-) mutation background with about 70% MMTV-Aurora-A;p53(+/-) animals developed tumors at 18 months of age. Of note, overexpression of Aurora-A led to genetic instability, characterized by centrosome amplification, chromosome tetraploidization and premature sister chromatid segregation, at stages prior to tumor formation. Most notably, the severe chromosomal abnormality did not cause cell death owing to the activation of AKT pathway, including elevated levels of phosphorylated AKT and mammalian target of rapamycin, and nuclear accumulation of cyclin D1, which enabled continuous proliferation of the tetraploid cells. These data establish Aurora-A as an oncogene that causes malignant transformation through inducing genetic instability and activating oncogenic pathways such as AKT and its downstream signaling.

Secretion of bacterial xenobiotic-degrading enzymes from transgenic plants by an apoplastic expressional system: an applicability for phytoremediation.

In search of an effective method for phytoremediation of wastewater contaminated with organic compounds, we investigated the application of an apoplastic expressional system that secretes useful bacterial enzymes from transgenic plants into hydroponic media through the addition of a targeting signal. We constructed transgenic Arabidopsis expressing the aromatic-cleaving extradiol dioxygenase (DbfB), which degrades 2,3-dihydroxybiphenyl (2,3-DHB), and transgenic tobacco expressing haloalkane dehalogenase (DhaA), which catalyzes hydrolytic dechlorination of 1-chlorobutane (1-CB). Although crude leaf extracts of transgenic plants expressing cytoplasm-targeted degradative enzymes showed higher activity than did those from transgenic plants expressing apoplast-targeted enzymes, the hydroponic media of the latter showed 23.2 times (DbfB) and 76.4 times (DhaA) higher activity than plants containing the cytoplasm-targeted enzymes. Addition of crystalline 2,3-DHB to 100 mL of the hydroponic medium of transgenic or wild-type seedlings revealed that only medium from the transgenic Arabidopsis expressing apoplast-targeted DbfB showed rapid ring cleavage of 2,3-DHB. Transgenic tobacco expressing apoplast-targeted DhaA also resulted in the accumulation of the dehalogenation product 1-butanol in the hydroponic medium and showed a higher tolerance to 1-CB than wild-type or transgenic plants expressing cytoplasm-targeted DhaA. These results demonstrate the usefulness of the apoplastic expression of bacterial recombinant proteins in phytoremediation.

Design of macromolecular prodrug of cisplatin using dextran with branched galactose units as targeting moieties to hepatoma cells.

We previously reported that a macromolecular prodrug synthesized by immobilizing cisplatin (CDDP) to dextran (Dex) through six-membered chelate-type coordination bond (DCM-Dex/CDDP conjugate) showed a significantly longer half-life in bloodstream and excellent in vivo tumor growth inhibitory effect against mice bearing Colon 26 cancer cells. In this report, to provide DCM-Dex/CDDP conjugate having targetability to hepatoma cells, we designed a new macromolecular prodrug of CDDP using dextran having branched galactose units (Gal4As, four branched galactose residues), DCM-Dex/Gal4A/CDDP conjugate. Galactose was employed as a homing device, because it is well-known that galactose receptors (asialoglycoprotein receptors) were exposed on the surface of liver parenchymal cells. The antennary (branched) structure of Gal4A was designed based on the fact that a saccharide cluster having a branched structure shows highly effective binding with the saccharide receptors, that is a "cluster effect". The apparent affinity constant per galactose residue against RCA120 lectin for dextran carrying Gal4As was higher than that for dextran carrying monomeric galactose residues. Moreover, the DCM-Dex/Gal4A/CDDP conjugate showed cell-specific cytotoxic activity against HepG2 human hepatoma cells in vitro. The cytotoxic activity of the conjugate was inhibited by the addition of galactose and strongly inhibited by the addition of Gal4A. The results suggest that the DCM-Dex/Gal4A/CDDP conjugate having branched galactose units has a higher affinity to hepatoma cells.

Diffuse intrasinusoidal liver metastasis of small cell lung cancer causing fulminant hepatic failure: CT findings-a case report.

A 65-year-old man with small cell lung cancer treated with two courses of chemotherapy manifested appetite loss and abdominal distention 10 days before admission. Helical CT scanning of the abdomen and pelvis disclosed marked hepatomegaly without any visible nodular lesion in the hepatic parenchyma. He died of severe liver dysfunction with multiorgan failure on the 20th hospital day. Autopsy revealed diffuse invasion of tumor cells into the sinusoid throughout the liver.

Enlarged focal nodular hyperplasia of the liver under the influence of oral contraceptives.

Two cases of focal nodular hyperplasia of the liver in mature women treated with the oral contraceptive are described. Radiological investigations in one case revealed the typical findings of focal nodular hyperplasia with computed tomography and magnetic resonance imaging demonstrating central scar structures while spoke-wheel appearance was evident on arteriography, in the other case however findings were atypical. Routine investigations including liver function tests and alpha-fetoprotein levels were normal while hepatitis B surface antigen and hepatitis C virus antibody were negative. The lesions of these two cases enlarged significantly during the follow-up and they were therefore surgically resected. Pathological features of both resected specimens, such as hepatocellular hyperplasia, bile duct proliferation and vascular abnormalities, were compatible with focal nodular hyperplasia. It has been suggested that tumor growth may be augmented by sex hormone stimulation and therefore estrogen and progesterone receptor expressions in the resected tumors were determined by immunocytochemistry. Interestingly, stainings for both receptors were negative. In case 2, the tumor was enlarging although oral contraceptive use had been discontinued for the past 7 years. These results suggest that there is no direct relationship of focal nodular hyperplasia with oral contraceptives. The role of sex hormones in focal nodular hyperplasia of the liver merits further study.

Tumor suppressor p53 is required to modulate BRCA1 expression.

Individuals carrying mutations in BRCA1 or p53 genes are predisposed to a variety of cancers, and both tumor suppressor genes have been implicated in DNA damage response pathways. We have analyzed a possible functional link between p53 and BRCA1 genes. Here we show that BRCA1 expression levels are down-regulated in response to p53 induction in cells that undergo either growth arrest, senescence, or apoptosis. Physiological stimuli, such as exposure to DNA-damaging agents, also result in negative regulation of BRCA1 levels in a p53-dependent manner prior to causing cell cycle arrest. Nuclear run-on experiments and luciferase reporter assays demonstrate that the changes in BRCA1 expression are mainly due to transcriptional repression induced by p53. In conclusion, the data show that BRCA1 expression levels are controlled by the presence and activity of wild-type p53 and suggest the existence of an intracellular p53/BRCA1 pathway in the response of cells to stress conditions.

Sustained activation of Ras/Raf/mitogen-activated protein kinase cascade by the tumor suppressor p53.

The p53 tumor suppressor gene can inhibit proliferation transiently, induce permanent cell-cycle arrest/senescence, or cause apoptosis depending on the cellular context. The mitogen-activated protein kinase (MAPK) cascade is known to play a crucial role in cell proliferation and differentiation. Moreover, the duration and intensity of MAPK activation can profoundly influence the biological response observed. We demonstrated that a sustained activation of MAPK cascade could be induced by wild-type p53 expression but not by p21(Waf1/Cip1). Furthermore, exposure of normal cells to DNA-damaging agents induced MAPK activation in a p53-dependent manner. Tumor-derived p53 mutants defective in DNA binding failed to activate MAPK, implying that p53 transcriptional activity is essential for this function. Finally, activation of MAPK by p53 was inhibited by expression of dominant-negative Ras (N17Ras) and Raf1 mutants, indicating that MAPK activation by p53 is mediated at a level upstream of Ras. All of these findings establish a biochemical link between p53 signaling and the Ras/Raf/MAPK cascade.

The kinase-deficient Src acts as a suppressor of the Abl kinase for Cbl phosphorylation.

The kinase activity of Abl is known to be regulated by a putative trans-acting inhibitor molecule interacting with the Src homology (SH) 3 domain of Abl. Here we report that the kinase-deficient Src (SrcKD) directly inhibits the tyrosine phosphorylation of Cbl and other cellular proteins by Abl. We found that both the SH2 and SH3 domains of SrcKD are necessary for the suppressor activity toward the Abl kinase phosphorylating Cbl. To suppress the Cbl phosphorylation by Abl, the interaction between the SH3 domain of SrcKD and Cbl is required. This interaction between SrcKD and Cbl is regulated by a closed structure of Cbl. The binding of Abl to the extreme carboxyl-terminal region of Cbl unmasks the binding site of SrcKD to Cbl. This results in a ternary complex that inhibits the Abl-mediated phosphorylation of Cbl by steric hindrance. These results illustrate a mechanism by which the enzymatically inactive Src can exert a biological function in vivo.

Collaboration of signal transducer and activator of transcription 1 (STAT1) and BRCA1 in differential regulation of IFN-gamma target genes.

Most of the activities of IFN-gamma are the result of STAT1-mediated transcriptional responses. In this study, we show that the BRCA1 tumor suppressor acts in concert with STAT1 to differentially activate transcription of a subset of IFN-gamma target genes and mediates growth inhibition by this cytokine. After IFN-gamma treatment, induction of the cyclin-dependent kinase inhibitor, p21WAF1, was synergistically activated by BRCA1, whereas the IRF-1 gene was unaffected. Importantly, the differential induction of p21WAF1 was impaired in breast cancer cells homozygous for the mutant BRCA1 5382C allele. Biochemical analysis illustrated that the mechanism of this transcriptional synergy involves interaction between BRCA1 aa 502-802 and the C-terminal transcriptional activation domain of STAT1 including Ser-727 whose phosphorylation is crucial for transcriptional activation. Significantly, STAT1 proteins mutated at Ser-727 bind poorly to BRCA1, reinforcing the importance of Ser-727 in the recruitment of transcriptional coactivators by STAT proteins. These findings reveal a novel mechanism for BRCA1 function in the IFN-gamma-dependent tumor surveillance system.

Antitumor activity of dextran derivatives immobilizing platinum complex (II).

The in vivo antitumor activity and toxicity of a newly synthesized polymeric prodrug of cisplatin was investigated and also compared with plain cisplatin. The prodrug included a dicarboxymethyl-dextran conjugate of cisplatin (DCM-Dex/CDDP). DCM-Dex/CDDP was i.v. injected in mice bearing s.c. Colon 26 mouse colon cancer cells. The tissue distribution of platinum was thereafter determined by flameless atomic absorption spectrophotometry. The platinic concentration of the organs showed a high rate of retention at 24 h after injection in the DCM-Dex/CDDP-treated mice. No biochemical or hematologically adverse effects were observed. In addition, DCM-Dex/CDDP showed a significantly higher antitumor activity than cisplatin alone. These results indicate that DCM-Dex/CDDP may therefore be a potentially effective cancer chemotherapy.

An ileostomy at the aganglionic ileum for total colon aganglionosis.

For the initial management of total colon aganglionosis (TCA), an ileostomy is usually created at the distal end of the ganglionic bowel, which is associated with profuse diarrhea resulting in a water and electrolyte imbalance as well as malnutrition during the ileostomy period. An ileostomy at the aganglionic ileum several centimeters toward the anal side of the transition for TCA is thus expected to cause bowel retention without any bowel obstruction and to facilitate water reabsorption in the small bowel. We performed this procedure in 2 babies with TCA. The length of the aganglionic ileum was 50 cm and 10 cm, respectively. The ileostomies were made 5 cm distal to the transition at 1 month and 1 day after birth, respectively. Oral feedings were well tolerated, resulting in adequate weight gain and the stools were semisolid during the ileostomy periods. Definitive operations using the Duhamel procedure with a right colon patch graft without the creation of a new ileostomy were successfully performed at 7 and 3 months of age, respectively. The postoperative courses were satisfactory. An ileostomy at the aganglionic ileum appears to be the method of choice as initial management for patients with TCA.

A case of biliary atresia with cystic dilatation of the extrahepatic bile duct and polysplenia syndrome.

A 79-day-old girl presented with jaundice and acholia. Laboratory findings disclosed elevated levels of bilirubin, transaminases, and gamma-glutamyl transferase. A chest X-ray film showed dextrocardia. A computed tomographic scan revealed a cystic mass at the porta hepatis, multiple spleens in the right side of the abdomen, and absence of the inferior vena cava. Under the diagnosis of biliary atresia (BA) (I-cyst) associated with polysplenia syndrome, a hepatic portojejunostomy was performed at 80 days of age. The postoperative course was uneventful, and the jaundice cleared. Although the occurrence of associated anomalies in BA is rare, polysplenia is most commonly seen, and its incidence is reported to be 2% to 10%. Patients with BA and polysplenia usually have a poor prognosis, however, this patient may have a good prognosis due to uneventful recovery from the jaundice.