Overexpression of KCNJ3 gene splice variants affects vital parameters of the malignant breast cancer cell line MCF-7 in an opposing manner.

BACKGROUND: Overexpression the KCNJ3, a gene that encodes subunit 1 of G-protein activated inwardly rectifying K(+) channel (GIRK1) in the primary tumor has been found to be associated with reduced survival times and increased lymph node metastasis in breast cancer patients. METHODS: In order to survey possible tumorigenic properties of GIRK1 overexpression, a range of malignant mammary epithelial cells, based on the MCF-7 cell line that permanently overexpress different splice variants of the KCNJ3 gene (GIRK1a, GIRK1c, GIRK1d and as a control, eYFP) were produced. Subsequently, selected cardinal neoplasia associated cellular parameters were assessed and compared. RESULTS: Adhesion to fibronectin coated surface as well as cell proliferation remained unaffected. Other vital parameters intimately linked to malignancy, i.e. wound healing, chemoinvasion, cellular velocities / motilities and angiogenesis were massively affected by GIRK1 overexpression. Overexpression of different GIRK1 splice variants exerted differential actions. While GIRK1a and GIRK1c overexpression reinforced the affected parameters towards malignancy, overexpression of GIRK1d resulted in the opposite. Single channel recording using the patch clamp technique revealed functional GIRK channels in the plasma membrane of MCF-7 cells albeit at very low frequency. DISCUSSION: We conclude that GIRK1d acts as a dominant negative constituent of functional GIRK complexes present in the plasma membrane of MCF-7 cells, while overexpression of GIRK1a and GIRK1c augmented their activity. The core component responsible for the cancerogenic action of GIRK1 is apparently presented by a segment comprising aminoacids 235-402, that is present exclusively in GIRK1a and GIRK1c, but not GIRK1d (positions according to GIRK1a primary structure). CONCLUSIONS: The current study provides insight into the cellular and molecular consequences of KCNJ3 overexpression in breast cancer cells and the mechanism upon clinical outcome in patients suffering from breast cancer.

Drug resistance pattern of Pseudomonas aeruginosa strains isolated from cystic fibrosis patients at Isfahan AL Zahra hospital, Iran (2009-2010).

BACKGROUND AND OBJECTIVES: Cystic fibrosis (CF) is an autosomal recessive genetic disease. Infections in these patients are mostly caused by three bacteria: Staphylococcus aureus, Haemophilus influenza and particularly Pseudomonas aeruginosa. Carbapenems including antibiotics are used to combat infections with Pseudomonas aeruginosa. In recent years, carbapenems resistant strains of P. aeruginosa isolated from clinical specimens are being reported. Decrease in drug penetration and production of metalobeta lactamase (MBLS) have been proposed as mechanisms of resistance. MATERIALS AND METHODS: In this descriptive study, the population under investigation was 27 patients suffering from CF in Alzahra hospital of Isfahan. Clinical specimens were taken by deep swabbing from throat and data from every patient was recorded in a questionnaire. The specimens were cultured and isolated organisms were identified as P. aeruginosa using standard tests. Kirby-Bauer disk diffusion method was used to determine the bacterial drug resistance pattern. Strains of P. aeruginosa were checked for production of MBLS using disk impregnated with IPM-EDTA and PCR targeting of bla(VIM). RESULTS: Among the 27 patients, 7 (26%) had P. aeruginosa infection. In total, 11 P. aeruginosa isolates were taken. All isolates were susceptible to imipenem, ticarcillin, ciprofloxacin and piperacillin. The lowest scale of susceptibility belonged to ceftazidime (72.2%) followed by tobramycin (45.4%). None of the strains were positive for the bla(VIM) gene. CONCLUSION: Isolates of P. aeruginosa from CF patients in Isfahan were susceptible to antibiotics during the study period.

Indoleamine 2,3-dioxygenase is expressed in the endometrium of cycling mice throughout the oestrous cycle.

Indoleamine 2,3-dioxygenase (IDO), an enzyme responsible for tryptophan catabolism, is thought to be required to prevent the rejection of the allogenic fetus by maternal T cells and to protect against intra- and extra-cellular pathogens. Consequently, we studied the expression of IDO in the endometrium of female Balb/c mice during the oestrous cycle. At each phase, the endometrium was peeled away and the relative expression of IDO mRNA was detected by semi-quantitative RT-PCR. The presence of IDO protein was confirmed in each phase by Western blotting and immunohistochemistry. Our results showed that IDO is expressed in the endometrium of cycling mice during all the phases of oestrous cycle. The expression of IDO was highest at the oestrus and lowest at the dioestrus. By means of Western blotting and immunohistochemistry, we obtained evidence that IDO protein is synthesised in the endometrium of cycling mice throughout the oestrous cycle. In accordance with RT-PCR results, IDO protein was predominant at the oestrus phase. IDO protein was mainly localised in the glandular and luminal epithelial cells. Our results support the concept of IDO providing a mechanism of innate immunity to protect from ascending infections of the female reproductive tract. In addition, considering the fact that mating only occurs during the oestrus phase, the high expression of IDO in this phase is likely to be a mechanism that induces immunological tolerance of the fetus.