Smac/DIABLO and colon cancer.

Apoptosis is a genetically programmed process of controlled and orderly cell suicide, which is critical for multicellular organisms during development and tissue homeostasis. In cancer, the ratio of apoptosis to cell division is altered, resulting in a net gain of malignant tissue. Tumor cells may acquire resistance to apoptosis by the expression of anti-apoptotic proteins, or by the down-regulation or mutation of pro-apoptotic mediators. In the classic pathway of apoptosis, this process is primarily coordinated by activation of caspases. Decreased expression of caspases inversely correlates with the aggressiveness of cancer. Increased activity of caspases renders cancer cells susceptible to chemoradiotherapeutic modalities. Thus, caspase activity is pivotal in carcinogenesis. The functions of activated caspases are inhibited by the binding of inhibitors of apoptosis (IAPs). The function of IAPs is regulated by pro-apoptotic protein Second Mitochondria-Derived Activator of Caspases (Smac) or Direct IAP Binding Protein with low isoelectric point, pI (DIABLO). Induction of apoptosis leads to increased mitochondrial permeability to Smac/DIABLO, which adheres to IAPs inhibiting their caspase-binding activity. The role of Smac/DIABLO, therefore, may have significant diagnostic and therapeutic features in carcinogenesis. The role of Smac/DIABLO in colorectal carcinogenesis is ill defined. Data continues to accumulate to suggest that decreased levels of Smac/DIABLO may be important in chemoradiation-resistance to apoptosis in advanced colon cancer. The aim of this review is to provide the available evidence of the role of Smac/DIABLO in colon carcinogenesis.

6-tioguanine monitoring in steroid-dependent patients with inflammatory bowel diseases receiving azathioprine.

BACKGROUND: 6-Thioguanine (6-tioguanine) nucleotides are the active metabolites of azathioprine. AIM: The aim of the study was to evaluate the rate of clinical remission without steroids in steroid-dependent Crohn's disease and ulcerative colitis patients receiving azathioprine, the medium- and long-term efficacy and the predictive factors of clinical response when monitoring 6-tioguanine. METHODS: Steroid-dependent Crohn's disease and ulcerative colitis patients receiving either azathioprine or not (treated later with a daily dose of 2.5 mg/kg) were prospectively included. 6-tioguanine was monitored at 1 and 2 months and every 3 months thereafter for 1 year. The azathioprine dose was adapted to reach a 6-tioguanine level of >250 pmol/8 x 10(8) red blood cells. Thiopurine methyltransferase genotype/phenotype was evaluated in some patients. RESULTS: A total of 106 patients were prospectively included (70 Crohn's disease, 36 ulcerative colitis). The clinical remission rate without steroids in patients receiving azathioprine, in intention-to-treat analysis, was 72% and 59% at 6 and 12 months, respectively. The remission rate was significantly higher in patients with 6-tioguanine >250 pmol/8 x 10(8) RBC (86% and 69% at 6 and 12 months, respectively; P < 0.01). No significant difference was observed between Crohn's disease and ulcerative colitis patients whether treated by azathioprine or not on inclusion. In the univariate analysis, the absence of Crohn's disease stenosis, a 6-tioguanine level >250 pmol/8 x 10(8) RBC, and an increase of erythrocyte mean corpuscular volume were the factors predictive of a favourable clinical response. In the multivariate analysis, only a 6-tioguanine level of >250 pmol/8 x 10(8) red blood cells was a predictive factor of favourable clinical remission. CONCLUSIONS: Clinical remission without steroids is significantly more likely when monitoring 6-tioguanine so as to reach a level of >250 pmol/8 x 10(8) red blood cells in steroid-dependent Crohn's disease and ulcerative colitis patients receiving azathioprine (86% and 69% at 6 and 12 months, respectively).

[Cow's milk protein allergy after neonatal intestinal surgery]. / Allergie aux protéines du lait de vache après chirurgie digestive néonatale.

UNLABELLED: Cases of cow's milk protein allergy have been occasionally reported after neonatal intestinal surgery. AIM OF THE STUDY: To measure the prevalence of cow's milk protein allergy (CMPA) following neonatal intestinal surgery. PATIENTS AND METHODS: The files of all children who underwent intestinal surgery in the neonatal period over a four-year-period were reviewed. The diagnosis of CMPA was made on the association of one or several symptoms suggesting food allergy after the introduction of cow's milk protein in the diet, the disappearance of the symptoms after exclusion of cow's milk protein from the diet and their reappearance after reintroduction of cow's milk protein. RESULTS: During the study period, 251 neonates underwent an intestinal surgery. Among them, 11 babies (4.3%) developed CMPA. None of them had a medical history of family atopy. Moreover, while 5 children were fed with a diet containing cow's milk protein before surgery: none of them presented initially with symptoms suggesting CMPA before intestinal surgery. Small intestine suffering was observed during operation in seven of 11 patients. No specific neonatal digestive disease or malformation was associated with CMPA. The signs revealing CMPA were primarily digestive : diarrhoea (N =3), vomiting (N =4), abdominal distension (N =2), colic or anorexia (N =2). Casein specific immunoglobulin E were present in nine of ten cases, alpha lactalbumin and/or beta lactoglobulin specific immunoglobulin E were present in six of ten cases. Prick test were performed in three children and were positive. CONCLUSION: The high prevalence of CMPA among these patients with no risk factors of allergy raises the question of the role of neonatal intestinal surgery in developing food allergy. These data should be confirmed by prospective case-control studies. They underline the interest to evoke the diagnosis of CMPA when digestive symptoms occur after milk protein introduction in children undergoing neonatal intestinal surgery. Breast feeding or milk protein hydrolysate formula should be used for refeeding these patients.

[Hypertrophic pulmonary osteo-arthropathy revealed by a pulmonary epithelioid hemangioendothelioma in a 15-year-old girl]. / Ostéo-arthropathie hypertrophiante pneumique et hémangio-endothéliome épithélioïde pulmonaire chez une adolescente de 15 ans.

UNLABELLED: Pulmonary epithelioid hemangioendothelioma is a rare vascular tumor of the lung, that may be revealed by hypertrophic pulmonary osteo-arthropathy. CASE REPORT: A 15-year-old patient was admitted because of a 1-month history of pneumonia associated with clubbing. A hypertrophic pulmonary osteo-arthropathy due to a paraneoplastic syndrome associated with lung epithelioid hemangioendothelioma was diagnosed. Despite surgical resection and chemotherapy, the patient died 6 months later. COMMENTS: Hypertrophic pulmonary osteo-arthropathy is a rare syndrome in childhood, and is frequently associated with chronic respiratory failure. Diagnosis is confirmed by long bones proliferative periostitis on standard X-ray examination. Pulmonary epithelioid hemangioendothelioma is a rare vascular malignant tumor, that spreads from the vascular pulmonary or hepatic tissues. The prognosis is variable, depending on the malignancy of the tumor. In the absence of a chronic cardiorespiratory disease, the diagnosis of a pulmonary hypertrophic osteo-arthropathy in childhood should prompt the search for a tumoral cause.

A Drosophila RNA helicase gene, pitchoune, is required for cell growth and proliferation and is a potential target of d-Myc.

This article describes the characterization of a new Drosophila gene that we have called pitchoune (pit) (meaning small in Provence) because mutations in this gene produce larvae that cannot grow beyond the first instar larval stage although they can live as long as 7-10 days. All the tissues are equally affected and the perfectly shaped larvae are indistinguishable from first instar wild-type animals. Analysis of mutant somatic clones suggests a function in cell growth and proliferation, which is supported by the fact that cell proliferation is promoted by pit overexpression. Tagged-Pit, when transfected in S2 cells, localizes mainly to the nucleolus, pointing towards a possible role in ribosome biogenesis and, consequently, in protein biosynthesis. pit encodes a DEAD-box RNA helicase, a family of proteins involved in the control of RNA structure in many cellular processes and its closest homologue is a human DEAD-box RNA helicase, MrDb, whose corresponding gene transcription is directly activated by Myc-Max heterodimers (Grandori, C., Mac, J., Siëbelt, F., Ayer, D. E. and Eisenman, R. N. (1996) EMBO J. 15, 4344-4357). The patterns of expression of d-myc and pit are superimposable. Ectopic expression of myc in the nervous system drives an ectopic expression of pit in this tissue indicating that in Drosophila as well, pit is a potential target of d-Myc. These results suggest that myc might promote cell proliferation by activating genes that are required in protein biosynthesis, thus linking cell growth and cell proliferation.