28 research outputs found
Neuropeptides, apoptosis and ion changes in prostate cancer. Methods of study and recent developments
It has been suggested that neuroendocrine
(NE) cells provide paracrine stimuli for the propagation
of local carcinoma cells and that NE differentiation is
associated with the progression of prostate cancer
toward an androgen-independent state. Apoptosis
comprises a critical intracellular defense mechanism
against tumorigenic growth and is associated with a
number of changes in the elemental content of the cell.
The neuropeptides bombesin and calcitonin, which
inhibit etoposide-induced apoptosis, also inhibit the
etoposide-induced elemental changes in prostate
carcinoma cells. This important fact strengthens the link
between apoptosis and changes in the intracellular
elemental content. This protective effect on etoposideinduced
apoptosis appears to be quite similar in
androgen-dependent and androgen-independent cell
lines. This confirms that neuropeptides confer
antiapoptotic capabilities on non-neuroendocrine cells in
close proximity to neuroendocrine cells. It can therefore
be speculated that certain neuroendocrine peptides can
increase the survival and further growth of neighboring
cells and may thereby contribute to the aggressive
clinical course of prostate tumors containing
neuroendocrine elements. In addition, this correlation
provides an objective basis for the study of neuropeptide
target points and may be helpful for alternative therapeutic protocols using neuropeptide inhibitors in the
treatment of patients with advanced prostatic carcinoma.
The culture techniques described were, thus, designed in
order to achieve two important goals. First, the
development of an in vitro model that allows an
approach to neuroendocrine differentiation in prostate
cancer and its role in apoptosis blockage. Second, the
method has been designed in order to permit rapid
cryofixation of intact cell monolayers for subsequent xray
microanalysis
Cystic fibrosis transmembrane conductance regulator (CFTR) activity in nasal epithelial cells from cystic fibrosis patients with severe genotypes
Moli1901 (duramycin) increases chloride transport in cystic fibrosis airway epithelial and pancreatic cell lines
26 CFTR and MDR mRNA expression in patients with Cystic Fibrosis before and after 6 months of Azithromycin
Effects of irradiation on intestinal cells in vivo and in vitro
The effects of irradiation on intestinal
epithelial cells were analyzed in vivo and in vitro. The in
vivo study was carried out on the rat small intestine and
for the in vitro study the intestinal crypt cell-line IEC-6
was used. Rat intestine and IEC-6 cells were irradiated
with X-ray doses ranging between 1-16 Gy. Energ y -
dispersive X-ray microanalysis was used for detection of
the elemental changes in the cells. Cell morphology was
investigated in the scanning electron microscope, DNAsynthesis
by autoradiography of 3H - t h y m i d i n e
incorporating nuclei and proliferation by cell counting.
Our results indicate that in vivo, in the crypt cells, the
increasing doses of irradiation led to increased sodium
and lowered potassium and phosphorus concentrations.
Corresponding ion shifts were found in the irradiated
IEC-6 cells. Cells continued to proliferate up to the dose
of 8 Gy, although the proliferation rate became lower
with increasing dose of irradiation. The increasing dose
of irradiation significantly reduced DNA-synthesis (16
Gy decreased DNA-synthesis by 50%) which resulted in
a complete inhibition of cell proliferation. Analysis of
goblet cells also showed characteristic radiationdependent
elemental changes. Scanning electron
microscopical investigation of cells in culture revealed
that most of the control cells were flat and had rather
smooth cell membranes. Irradiation led to the
appearance of numerous different membrane
manifestations (microvilli of varying length and
distribution, and blebs). Frequency of differences in the
topology of the cells was related to the dose of
irradiation. Our study clearly demonstrates that even low
doses of irradiation cause changes in the ionic
composition of the cells and inhibit DNA-synthesis and
cell proliferation. The effects observed in the crypt cells
in vivo were the same as in the intestinal cell line i n
v i t ro, which indicates that IEC-6 cells can be used for
investigation of side effects of radiation to the abdomen