E-Cadherin in Colorectal Cancer: Relation to Chemosensitivity

Background

The conventional chemotherapy of colorectal cancer with irinotecan, 5-fluorouracil, and oxaliplatin remains one of the front-line treatments worldwide. However, its efficacy is quite low. Recently studies of the epithelial–mesenchymal transition (EMT) have become the focus of investigations into the cause of chemoresistance in several types of cancer, including colorectal cancer. The data about the role of EMT in chemosensitivity are controversial.

Exome sequencing and case–control analyses identify RCC1 as a candidate breast cancer susceptibility gene

Breast cancer is a genetic disease but the known genes explain a minority of cases. To elucidate the molecular basis of breast cancer in the Tunisian population, we performed exome sequencing on six BRCA1/BRCA2 mutation‐negative patients with familial breast cancer and identified a novel frameshift mutation in RCC1, encoding the Regulator of Chromosome Condensation 1. Subsequent genotyping detected the 19‐bp deletion in additional 5 out of 153 (3%) breast cancer patients but in none of 400 female controls (p = 0.0015). The deletion was enriched in patients with a positive family history (5%, p = 0.0009) and co‐segregated with breast cancer in the initial pedigree. The mutant allele was lost in 4/6 breast tumors from mutation carriers which may be consistent with the hypothesis that RCC1 dysfunction provides a selective disadvantage at the stage of tumor progression. In summary, we propose RCC1 as a likely breast cancer susceptibility gene in the Tunisian population.     

Experimental validation for the use of recombinant prourokinase and its immobilized forms in the treatment of postoperative fibrinoid syndrome in ophthalmology

The specific therapeutic effectiveness of a single intravitreal injection of native and immobilized recombinant prourokinase is assessed in lensvitrectomized rabbits with the fibrinoid syndrome. The agents almost completely lyse the fibrin clot within 1–8 h. Heteroprotein conjugates of protein kinase with molecular weight of 900 kD and high fibrinolytic activity at 2–20-fold lower doses of the enzyme are preferable. Native and immobilized prourokinase are recommended for clinical use in case of intraocular fibrin formation after lensvitrectomy and other operations. Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 2, pp. 201–204, February, 1997     

The effect of a nitric oxide donor on the synthesis of cGMP in Hymenolepis diminuta: a radiometric study

The formation of cGMP in homogenates of the adult rat-tapeworm Hymenolepis diminuta was followed with a radiometric assay during 3 h after stimulation with the nitric oxide donor sodium nitroprusside (SNP) and in the presence of isobutylmethylxanthine (IBMX). The level of cGMP was stable in worms incubated with IBMX during the first hour. After 3 h of incubation, the level of cGMP had declined by 27%. Addition of SNP stimulated the formation of cGMP during the first hour of incubation. After 3 h of incubation, a two-fold decline in cGMP formation was observed. The rate of nitric oxide (NO) release by the worm was determined by a spectrophotometric assay for the accumulation of nitrites and nitrates, the stable degradation products of NO, using the Griess reaction. The results are discussed from the perspective of the current concept on the role of the nitrergic mechanisms in the flatworm nervous system.     

Polymorphism in the CD5 gene promoter in B-cell chronic lymphocytic leukemia and mantle cell lymphoma

Despite the low incidence of microsatellite instability (MSI) in lymphoid malignant neoplasms, it has been reported that the CD5 promoter MSI was relatively frequent among B-cell chronic lymphoproliferative disorders. We studied the presence of MSI in the CD5 promoter in 134 cases of B-cell chronic lymphocytic leukemia (B-CLL) and 47 of mantle cell lymphoma (MCL) by comparing the pattern of microsatellite repeats on autologous germline and tumor DNA samples. Microsatellite alterations were not observed in any case. However, the allele distribution of this polymorphism showed a higher frequency of the 18 CA allele (0.585) in MCL cases (P = .026; odds ratio [OR], 1.75; 95% confidence interval [CI], 1.07-2.87) and of the 19 CA allele (0.179) in B-CLL cases (P = .005; OR, 2.26; 95% CI, 1.27-4.01) compared with control cases (0.442 and 0.087, respectively). This suggests that although MSI seems not to be involved in the pathogenesis of these 2 lymphoid malignant neoplasms, the polymorphic CD5 promoter is associated with increased susceptibility to these disorders.