Clinical usefulness of mtTFA expression as a predictive marker in colorectal cancer patients treated with FOLFOX

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Background: We previously reported that mitochondrial transcription factor A (mtTFA; also designated Tfam) preferentially recognizes cisplatin-damaged DNA via physical interaction with p53 and is upregulated by the treatment with cisplatin and 5-FU (Yoshida et al, Cancer Res. 2003). The aim of this study was to evaluate whether expression of mtTFA predicts clinical outcome in patients with metastatic colorectal cancer treated with modified FOLFOX6 (mFOLFOX6). Methods: From January 2006 to April 2008, 59 patients who had metastatic lesions from colorectal cancer treated with mFOLFOX6 at the Osaka Rosai Hospital were included in this study. They consisted of 25 women (42.4%) and 34 men (57.6%), with a median age of 62 years (29–84). Patients were treated with oxaliplatin 85mg/m2 plus leucovorin 200mg/m2 as a 2-h infusion at day 1, followed by 5-FU bolus 400mg/m2 and 46-h continuous infusion of 2400 mg/m2. Treatment was repeated in 2-week intervals for at least 4 cycles. The expressions of mtTFA and p53 of resected primary tumors were examined by immunohistochemistry. Results: Among 59 patients, one complete response and 32 partial responses were observed (response rate, 55.9%) . The positive rates was 44.1% (26/59; CR 1, PR 7, SD/PD 18) for mtTFA and 59.3% (35/59; CR 1, PR 19, SD/PD 15) for p53, respectively. Strong expression of mtTFA was detected in 8 of 33 CR/PR (24.2%) and in 18 of 26 SD/PD (69.2%), indicating that the expression of mtTFA correlated significantly with response to chemotherapy (P<0.01). On the other hand, there was no significant correlation between response to chemotherapy and p53 expression (P=0.82). mtTFA expression was significantly associated with overall survival (P=0.036) and progression free survival (P=0.037). Multivariate analysis revealed that mtTFA expression significantly impacted on OS (Hazard ratio 2.10, P=0.036). Conclusions: Immunohistochemical study of mtTFA may be useful in prediction of the clinical outcome of metastatic colorectal cancer patients treated with FOLFOX.

No significant financial relationships to disclose.

IgE antibodies to omega-5 gliadin associate with immediate symptoms on oral wheat challenge in Japanese children

BACKGROUND

Gliadins have been implicated in immunoglobulin E (IgE)-mediated allergy to ingested wheat and omega-5-gliadin is known to represent a major allergen in wheat-dependent exercise-induced anaphylaxis. Less known is whether omega-5-gliadin is a clinically relevant allergen in children with immediate allergy to ingested wheat. This study investigates whether specific IgE antibodies to omega-5-gliadin (sIgE-omega-5-gliadin-ab) could be used as a marker for oral wheat challenge outcome in wheat-sensitized children. A secondary objective was to study whether the level of sIgE-omega-5-gliadin was related to symptom severity in children with a positive challenge test.

METHODS

Serum samples from 88 children sensitized to wheat, of whom 35 underwent wheat challenge, were collected consecutively. sIgE-omega-5-gliadin-ab was related to a physician's diagnosis of wheat allergy and challenge symptoms.

RESULTS

The mean concentration of sIgE-omega-5-gliadin-ab was 7.25 kU(A)/l in patients with wheat allergy and 1.08 kU(A)/l in patients with no wheat allergy (P < 0.01). sIgE-omega-5-gliadin-ab was only detected in 12 of the non-wheat allergic children and 11 of them had a specific IgE to wheat below 1.30 kU(A)/l. Children reacting with severe symptoms upon challenge (n = 8) had increased levels of sIgE-omega-5-gliadin-ab compared to children with moderate, mild or no symptoms (P < 0.001).

CONCLUSIONS

The presence of sIgE-omega-5-gliadin-ab is related to the reaction level to wheat challenge outcome in wheat-sensitized children. The sIgE-omega-5-gliadin-ab was found to be associated with a strong convincing history of wheat allergy also in those cases when oral food challenge was avoided. The sIgE-omega-5-gliadin-ab level may serve as a marker for clinical reactivity in wheat-sensitized individuals.

Role of platelets on liver regeneration after 90% hepatectomy in mice

BACKGROUND/AIMS

Mortality after 90% partial hepatectomy in mice was associated with severe acute liver failure. Recently, we revealed that platelets have a strong promotional effect on hepatic regeneration. In the present study, we investigated the effect of thrombocytosis on liver regeneration after 90% hepatectomy in mice.

METHODS

For thrombocytosis induction PEG-rHuMGDF was injected 5 days before operation. Hepatectomy, sparing only the caudate lobe, was performed in normal and thrombocytotic BALB/c mice. Survival rate, platelet number, liver weight/body weight ratio, proliferating cell nuclear antigen, serum parameters, signal transduction and overexpressed genes were examined.

RESULTS

Platelet number was significantly higher in thrombocytotic group. All mice in normal group died within 30 h after hepatectomy. Survival rate in thrombocytotic group was 6/11 at 30 h and 3/11 one week after hepatectomy. Activation of Akt and STAT3 signaling pathways in thrombocytotic group was observed earlier and recognized to be stronger compared to normal group. Cell cycle, signaling pathways, metabolism and transport genes were significantly overexpressed in thrombocytotic group up to 24h after hepatectomy.

CONCLUSIONS

Under the thrombocytotic condition, liver regeneration occurred even in 90% hepatectomized mice. Platelets contribute to cell cycle progression and metabolic pathways in addition to preventing acute liver failure.

Chromosomal location of Lg-FLO1 in bottom-fermenting yeast and the FLO5 locus of industrial yeast

AIMS

To determine the chromosomal location and entire sequence of Lg-FLO1, the expression of which causes the flocculation of bottom-fermenting yeast.

METHODS AND RESULTS

Two cosmid clones carrying DNA from a bottom-fermenting yeast chromosome VIII right-arm end were selected by colony hybridization. Sequencing revealed that the clones contained DNA derived from a Saccharomyces cerevisiae type chromosome VIII and a Saccharomyces bayanus type chromosome VIII, both from bottom-fermenting yeast.

CONCLUSIONS

Lg-FLO1 is located on the S. cerevisiae type chromosome VIII at the same position as the FLO5 gene of the laboratory yeast S. cerevisiae S288c. The unique chromosome VIII structure of bottom-fermenting yeast is conserved among other related strains. FLO5 and Lg-FLO1 promoter sequences are identical except for the presence of three 42 bp repeats in the latter, which are associated with gene activity. Flocculin genes might have been generated by chromosomal recombination at these repeats.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report of the exact chromosomal location and entire sequence of Lg-FLO1. This information will be useful in the brewing industry for the identification of normal bottom-fermenting yeast. Moreover, variations in the FLO5 locus among strains are thought to reflect yeast evolution.

Autonomic regulation of liver regeneration after partial hepatectomy in mice

BACKGROUND/AIMS

The autonomic vagus nerve is thought to play an essential role in liver regeneration since hepatic vagotomy delays hepatic DNA synthesis. However, how the parasympathetic vagus nerve is involved in liver regeneration remains obscure. Kupffer cells are located in liver sinusoids adjacent to hepatocytes and might regulate liver regeneration by releasing interleukin-6 (IL-6). The present study examines the role of the vagus nerve and how Kupffer cells are involved in parasympathetic nerve-mediated liver regeneration in mice.

METHODS

We performed surgical vagotomy of the hepatic branch and then partial hepatectomy (PH); some mice received acetylcholine (ACh) agonist/antagonist before PH. We then evaluated liver regeneration and signal transducer and activator of transcription-3 (STAT3) activation. We also investigated whether ACh stimulates IL-6 release from Kupffer cells.

RESULTS

Surgical vagotomy impaired liver regeneration. STAT3, which is activated by IL-6 after hepatectomy and plays a pivotal role in liver regeneration, was less activated in vagotomized mice after PH. Post-PH STAT3 activation was recovered by administering vagotomized mice with an ACh agonist. Furthermore, ACh stimulated IL-6 release in Kupffer cells in vitro.

CONCLUSION

The parasympathetic system (vagus nerve) contributes to liver regeneration after hepatectomy by stimulating IL-6 release from Kupffer cells followed by STAT3 activation in hepatocytes.

Sensitivity and specificity of recombinant omega-5 gliadin-specific IgE measurement for the diagnosis of wheat-dependent exercise-induced anaphylaxis

BACKGROUND

A recent study has shown that the measurement of specific IgE antibodies to B-cell epitope peptides of wheat omega-5 gliadin (Pep A) and high molecular weight glutenin subunit (Pep B) are useful to diagnose wheat-dependent exercise-induced anaphylaxis (WDEIA).

AIMS OF THE STUDY

We sought to compare the sensitivity and specificity of the in vitro tests for measuring the specific IgE antibodies to recombinant omega-5 gliadin (romega-5 gliadin) with those for wheat, gluten, Pep A, and Pep B in identification of patients with WDEIA.

METHODS

Fifty patients with WDEIA, 25 healthy subjects and 25 patients with atopic dermatitis with specific IgE antibodies to wheat but without experience of allergic reactions after ingestion of wheat products were enrolled in this study. The concentrations of specific IgE antibodies were measured using ImmunoCAP. The empirical receiver operating characteristics curves (ROC) for each test were prepared and the areas under the ROC curve (AUC) were compared.

RESULTS

In patients with WDEIA, the sensitivities of the allergen-specific IgE tests for wheat, gluten, Pep A, Pep B and romega-5 gliadin were 48%, 56%, 76%, 22%, and 80%, respectively. The seven of 10 WDEIA patients with no specific IgE antibodies to romega-5 gliadin had specific IgE antibodies to Pep B. The highest AUC (0.850) was observed in the test for romega-5 gliadin.

CONCLUSIONS

Measuring the concentration of specific IgE antibodies to romega-5 gliadin is more useful than to wheat, gluten, or Pep A in the identification of patients with WDEIA.

Platelet dynamics in the early phase of postischemic liver in vivo

BACKGROUND

In liver surgery, ischemia/reperfusion injury occasionally leads to liver failure by activating Kupffer cells (KCs) and leukocytes. However, few reports have demonstrated a relationship between KCs and platelets in vivo. This study investigated the relationship between these cells using intravital microscopy.

MATERIALS AND METHODS

Male Wistar rats were divided into two groups: (1) KC+ group, receiving 1 mL saline; and (2) KC- group, intravenously injected with liposome-encapsulated dichloromethylene disphosphonate for elimination of KCs. At 48 h after administration, 20 min of total normothermic hepatic ischemia was induced. Rhodamine-6G-labeled platelets and sinusoidal alterations were monitored using intravital microscopy up to 120 min after reperfusion. P-selectin, accumulated leukocytes and morphological damage, and alanine aminotransferase were evaluated.

RESULTS

In the KC+ group, numbers of adherent platelets increased significantly within 30 min after reperfusion. Endothelial cells of sinusoids in which KCs were mainly located were destroyed and the sinusoids were significantly constricted after reperfusion. Conversely, in the KC- group, adherent platelets in sinusoids were suppressed, and sinusoidal perfusion, endothelial cell damage and serum alanine aminotransferase levels were significantly improved. P-selectin on sinusoidal endothelial cells was not observed up to 120 min after reperfusion in either group.

CONCLUSIONS

Adherent platelets appear to reflect activation of KCs and lead to leukocyte accumulation, resulting in sinusoidal perfusion disturbance and liver failure. Evaluation of adherent platelets in the microcirculation offers an important marker of hepatic injury.

ZNF143 interacts with p73 and is involved in cisplatin resistance through the transcriptional regulation of DNA repair genes

Zinc-finger protein 143 (ZNF143) is a human homolog of Xenopus transcriptional activator staf that is involved in selenocystyl tRNA transcription. We previously showed that ZNF143 expression is induced by treatment with DNA-damaging agents and that it preferentially binds to cisplatin-modified DNA. In this study, the potential function of ZNF143 was investigated. ZNF143 was overexpressed in cisplatin-resistant cells. ZNF143 knockdown in prostate cancer caused increased sensitivity for cisplatin, but not for oxaliplatin, etoposide and vincristine. We also showed that ZNF143 is associated with tumor suppressor gene product p73 but not with p53. p73 could stimulate the binding of ZNF143 to both ZNF143 binding site and cisplatin-modified DNA, and modulate the function of ZNF143. We provide a direct evidence that both Rad51 and flap endonuclease-1 are target genes of ZNF143 and overexpressed in cisplatin-resistant cells. Taken together, these experiments demonstrate that an interplay of ZNF143, p73 and ZNF143 target genes is involved in DNA repair gene expression and cisplatin resistance.

Clock and ATF4 transcription system regulates drug resistance in human cancer cell lines

The mechanisms underlying cellular drug resistance have been extensively studied, but little is known about its regulation. We have previously reported that activating transcription factor 4 (ATF4) is upregulated in cisplatin-resistant cells and plays a role in cisplatin resistance. Here, we find out a novel relationship between the circadian transcription factor Clock and drug resistance. Clock drives the periodical expression of many genes that regulate hormone release, cell division, sleep-awake cycle and tumor growth. We demonstrate that ATF4 is a direct target of Clock, and that Clock is overexpressed in cisplatin-resistant cells. Furthermore, Clock expression significantly correlates with cisplatin sensitivity, and that the downregulation of either Clock or ATF4 confers sensitivity of A549 cells to cisplatin and etoposide. Notably, ATF4-overexpressing cells show multidrug resistance and marked elevation of intracellular glutathione. The microarray study reveals that genes for glutathione metabolism are generally downregulated by the knockdown of ATF4 expression. These results suggest that the Clock and ATF4 transcription system might play an important role in multidrug resistance through glutathione-dependent redox system, and also indicate that physiological potentials of Clock-controlled redox system might be important to better understand the oxidative stress-associated disorders including cancer and systemic chronotherapy.

Oral adsorbent AST-120 decreases serum levels of AGEs in patients with chronic renal failure

Advanced glycation end products (AGEs) are senescent macroprotein derivatives that are formed at an accelerated rate in patients with chronic renal failure (CRF). AGE formation and accumulation in plasma and vascular tissues contribute to accelerated atherosclerosis in this devastating disorder. AST-120 is an oral adsorbent that attenuates the progression of CRF by removing uremic toxins. Recently, AST-120 has been reported to reduce the progression of atherosclerosis as well. However, whether AST-120 decreases serum levels of AGEs and subsequently exerts atheroprotective properties remains to be elucidated. Ten nondiabetic CRF patients were enrolled in this study. All patients were kept on regular therapeutic diet and medications throughout the study. Serum AGE levels before and after AST-120 treatments were measured using enzyme-linked immunosorbent assay. Effects of patient-derived serum on atherosclerosis-related gene expression in cultured human umbilical vein endothelial cells (HUVECs) were analyzed by semiquantitative RT-PCR. Administration of AST-120 (6 g/day) for 3 months significantly decreased serum levels of AGEs in nondiabetic CRF patients, whereas AGE levels remained unchanged in age- and renal function-matched CRF patients without AST-120 treatment (n = 6). Patient serum after AST-120 treatment significantly reduced mRNA levels of receptor for AGEs, monocyte chemoattractant protein-1, and vascular adhesion molecule-1 in HUVECs compared with serum before treatment. Moreover, in vitro, AST-120 was found to adsorb carboxymethyllysine (CML), one of the well-characterized, digested food-derived AGEs. This study suggests that atheroprotective properties of AST-120 can be ascribed, at least in part, to its AGE-lowering ability via absorption of CML.

Oral adsorbent AST-120 decreases serum levels of AGEs in patients with chronic renal failure

Advanced glycation end products (AGEs) are senescent macroprotein derivatives that are formed at an accelerated rate in patients with chronic renal failure (CRF). AGE formation and accumulation in plasma and vascular tissues contribute to accelerated atherosclerosis in this devastating disorder. AST-120 is an oral adsorbent that attenuates the progression of CRF by removing uremic toxins. Recently, AST-120 has been reported to reduce the progression of atherosclerosis as well. However, whether AST-120 decreases serum levels of AGEs and subsequently exerts atheroprotective properties remains to be elucidated. Ten nondiabetic CRF patients were enrolled in this study. All patients were kept on regular therapeutic diet and medications throughout the study. Serum AGE levels before and after AST-120 treatments were measured using enzyme-linked immunosorbent assay. Effects of patient-derived serum on atherosclerosis-related gene expression in cultured human umbilical vein endothelial cells (HUVECs) were analyzed by semiquantitative RT-PCR. Administration of AST-120 (6 g/day) for 3 months significantly decreased serum levels of AGEs in nondiabetic CRF patients, whereas AGE levels remained unchanged in age- and renal function-matched CRF patients without AST-120 treatment (n = 6). Patient serum after AST-120 treatment significantly reduced mRNA levels of receptor for AGEs, monocyte chemoattractant protein-1, and vascular adhesion molecule-1 in HUVECs compared with serum before treatment. Moreover, in vitro, AST-120 was found to adsorb carboxymethyllysine (CML), one of the well-characterized, digested food-derived AGEs. This study suggests that atheroprotective properties of AST-120 can be ascribed, at least in part, to its AGE-lowering ability via absorption of CML.

Mesangiolytic glomerulopathy after radiotherapy and chemotherapy of gastric lymphoma

Mesangiolytic glomerulopathy is an uncommon complication of irradiation and chemotherapy of THP-COP [pirarubicin, cyclophosphamide (CPA), vincristin (VCR), predonisolone (PSL)] and CHOP (CPA, Doxorubicin, VCR, PSL). We report a case of 63-year-old man 7 months status post radiation, and 10 months post chemotherapy for gastric lymphoma. The patient showed proteinuria and mild renal insufficiency. Renal biopsy revealed marked mesangiolysis in the glomeruli without any immune depositions. After the administration of angiotensin II receptor blocker, the patient's renal function remained stable for over two years. Mesangiolysis was thought to be a characteristic glomerular lesion in this patient treated with both chemoagents and radiation.

Carbonic-adsorbent AST-120 reduces overload of indoxyl sulfate and the plasma level of TGF-β1 in patients with chronic renal failure

BACKGROUND

We previously reported a significant increase in plasma TGF-beta1 in patients with chronic renal failure (CRF). Progression of CRF may be caused by persistent renal production of TGF-beta1. In CRF rat models, an oral carbonic absorbent (AST-120) reduces the expression of the TGF-beta1 gene in the kidney, and delays the progression of CRF, in part by alleviating the overload of indoxyl sulfate. The aim of this study was to evaluate the effect of AST-120 on plasma levels of indoxyl sulfate and TGF-beta1 in CRF patients.

METHODS

Ten CRF patients (aged 59.3 +/- 9.5 years, 5 men, serum creatinine 4.37 +/- 1.72 mg/dl) were enrolled in this study. All patients maintained a regular dietary therapy and the same medication throughout the study. AST-120 was added at a dose of 6 g/day. Parameters including the slope of the reciprocal of the serum creatinine-time plot, plasma indoxyl sulfate level, and plasma and urinary levels of TGF-beta1 were compared before and after the treatment with AST-120. The mean observation periods before and after the treatment were 9.7 +/- 2.8 and 6.5 +/- 2.9 months, respectively.

RESULTS

Administration of AST-120 significantly reduced the plasma levels of indoxyl sulfate (1.42 +/- 1.50 vs. 1.26 +/- 1.40 mg/dl, P < 0.05) and TGF-beta1 (17.9 +/- 7.2 vs. 10.6 +/- 4.7 ng/ml, P < 0.05) and improved the slope of the reciprocal of serum creatinine (-0.061 +/- 0.041 vs. -0.032 +/- 0.055 dl/mg/year, P < 0.05).

CONCLUSIONS

These results support the notion that indoxyl sulfate and TGF-beta1 may be involved in the progression of CRF, and that the oral adsorbent AST-120 may suppress the progression, at least in part, by reducing overproduction of TGF-beta1.

Akt-dependent nuclear localization of Y-box-binding protein 1 in acquisition of malignant characteristics by human ovarian cancer cells

Y-box-binding protein 1 (YB-1), which is a member of the DNA-binding protein family containing a cold-shock domain, has pleiotropic functions in response to various environmental stimuli. As we previously showed that YB-1 is a global marker of multidrug resistance in ovarian cancer and other tumor types. To identify YB-1-regulated genes in ovarian cancers, we investigated the expression profile of YB-1 small-interfering RNA (siRNA)-transfected ovarian cancer cells using a high-density oligonucleotide array. YB-1 knockdown by siRNA upregulated 344 genes, including MDR1, thymidylate synthetase, S100 calcium binding protein and cyclin B, and downregulated 534 genes, including CXCR4, N-myc downstream regulated gene 1, E-cadherin and phospholipase C. Exogenous serum addition stimulated YB-1 translocation from the cytoplasm to the nucleus, and treatment with Akt inhibitors as well as Akt siRNA and integrin-linked kinase (ILK) siRNA specifically blocked YB-1 nuclear localization. Inhibition of Akt activation downregulated CXCR4 and upregulated MDR1 (ABCB1) gene expression. Administration of Akt inhibitor resulted in decrease in nuclear YB-1-positive cancer cells in a xenograft animal model. Akt activation thus regulates the nuclear translocation of YB-1, affecting the expression of drug-resistance genes and other genes associated with the malignant characteristics in ovarian cancer cells. Therefore, the Akt pathway could be a novel target of disrupting the nuclear translocation of YB-1 that has important implications for further development of therapeutic strategy against ovarian cancers.

Expression of Y-box-binding protein dbpC/contrin, a potentially new cancer/testis antigen

Y-box-binding proteins are members of the human cold-shock domain protein superfamily, which includes dbpA, dbpB/YB-1, and dbpC/contrin. dbpC/contrin is a germ cell-specific Y-box-binding protein and is suggested to function as a nuclear transcription factor and RNA-binding protein in the cytoplasm. Whereas ubiquitous dbpB/YB-1 expression has been well studied in various types of human carcinomas as a prognostic or predictive marker, the dbpC/contrin expression in human tumour cells has not been reported. In this report, we provide the first evidence showing that dbpC was highly expressed in human testicular seminoma and ovarian dysgerminomas, and in carcinomas in other tissues and that its expression in normal tissues is nearly restricted to germ cells and placental trophoblasts. These results indicate that dbpC/contrin would be a potentially novel cancer/testis antigen.

Roles of volume-sensitive Cl- channel in cisplatin-induced apoptosis in human epidermoid cancer cells

The anti-cancer drug cisplatin induces apoptosis by damaging DNA. Since a stilbene-derivative blocker of Cl-/HCO3- exchangers and Cl- channels, SITS, is known to induce cisplatin resistance in a manner independent of intracellular pH and extracellular HCO3-, we investigated the relation between cisplatin-induced apoptosis and Cl- channel activity in human adenocarcinoma KB cells. A stilbene derivative, DIDS, reduced cisplatin-induced caspase-3 activation and cell death, which were detected over 18 h after treatment with cisplatin. DIDS was also found to reduce sensitivity of KB cells to 5-day exposure to cisplatin. Whole-cell patch-clamp recordings showed that KB cells functionally express volume-sensitive outwardly rectifying (VSOR) Cl- channels which are activated by osmotic cell swelling and sensitive to DIDS. Pretreatment of the cells with cisplatin for 12 h augmented the magnitude of VSOR Cl- current. Thus, it is concluded that cisplatin-induced cytotoxicity in KB cells is associated with augmented activity of a DIDS-sensitive VSOR Cl- channel and that blockade of this channel is, at least in part, responsible for cisplatin resistance induced by a stilbene derivative.