Influence of partial and complete glutamine-and glucose deprivation of breast-and cervical tumorigenic cell lines

Abstract

BackgroundDue to their high proliferative requirements, tumorigenic cells possess altered metabolic systems whereby cells utilize higher quantities of glutamine and glucose. These altered metabolic requirements make it of interest to investigate the effects of physiological non-tumorigenic concentrations of glucose and glutamine on tumorigenic cells since deprivation of either results in a canonical amino acid response in mammalian cell.MethodsThe influence of short-term exposure of tumorigenic cells to correlating decreasing glutamine- and glucose quantities were demonstrated in a highly glycolytic metastatic breast cell line and a cervical carcinoma cell line. Thereafter, cells were propagated in medium containing typical physiological concentrations of 1 mM glutamine and 6 mM glucose for 7 days. The effects on morphology were investigated by means of polarization-optical transmitted light differential interference contrast. Flow cytometry was used to demonstrate the effects of glutamine-and glucose starvation on cell cycle progression and apoptosis induction. Fluorometrics were also conducted to investigate the effects on intrinsic apoptosis induction (mitocapture), reactive oxygen species production (2,7-dichlorofluorescein diacetate) and acidic vesicle formation (acridine orange).ResultsMorphological data suggests that glutamine-and glucose deprivation resulted in reduced cell density and rounded cells. Glutamine-and glucose starvation also resulted in an increase in the G2M phase and a sub-G1 peak. Complete starvation of glutamine and glucose resulted in the reduction of the mitochondrial membrane potential in both cell lines with MDA-MB-231 cells more prominently affected when compared to HeLa cells. Further, starved cells could not be rescued sufficiently by propagating since cells possessed an increase in reactive oxygen species, acidic compartments and vacuole formation.ConclusionStarvation from glutamine and glucose for short periods resulted in decreased cell density, rounded cells and apoptosis induction by means of reactive oxygen species generation and mitochondrial dysfunction. In addition, the metastatic cell line reacted more prominently to glutamine-and glucose starvation due to their highly glycolytic nature. Satisfactory cellular rescue was not possible as cells demonstrated oxidative stress and depolarized mitochondrial membrane potential. This study contributes to the knowledge regarding the in vitro effects and signal transduction of glucose and/or l-glutamine deprivation in tumorigenic cell lines.

In vitro assessment of a computer-designed potential anticancer agent in cervical cancer cells

“…The HeLa cell line is the oldest and utmost circulated immortalized cell line that presents with aggressive growth and is derived from cervical adenocarcinoma [16, 17]. HeLa cells were obtained from Hendrietta Lacks, a cervical cancer patient in 1951.…”

“…Polarization-optical transmitted light differential interference contrast (PlasDIC) is a method where the cells are illuminated with non-polarized light rendering improved contrast and a clear image [17, 20–22]. PlasDIC provides reproducibly high-quality imaging of individual cells, cell clusters creating a relief-type impression regardless of the of the plastic cell culture vessels thickness compared to the glass-bottom vessels required for differential interference contrast techniques [17, 18].…”

“…PlasDIC provides reproducibly high-quality imaging of individual cells, cell clusters creating a relief-type impression regardless of the of the plastic cell culture vessels thickness compared to the glass-bottom vessels required for differential interference contrast techniques [17, 18]. Images were captured before and after the exposure by means of the Axiovert 40 CFL microscope (Carl Zeiss, Gottingen, Germany).…”

Reactive oxygen species (ROS) are a key determinant of cancer's metabolic phenotype

“…Aggressive cancers in particular are found to have a dependence on glutamine availability . While glutaminolysis does play an important role in replenishing metabolic intermediates, its importance for redox is underappreciated.…”

“…77 Aggressive cancers in particular are found to have a dependence on glutamine availability. [78][79][80] While glutaminolysis does play an important role in replenishing metabolic intermediates, its importance for redox is underappreciated. Glutamine can increase antioxidant capacity since it is a precursor for glutathione and can also help import cysteine through the xCT antiporter.…”