Analysis of hypoxia‐inducible factor‐1α accumulation and cell cycle in geldanamycin‐treated human cervical carcinoma cells by laser scanning cytometry

Abstract

Background: Tumor hypoxia has been linked to increased disease aggressiveness and poorer treatment outcomes, and the transcription factor hypoxia-inducible factor-1 (HIF-1) has been identified as the key molecule mediating the cellular response to hypoxic microenvironments. The a-subunit of this factor is accumulated under hypoxia and rapidly degraded during re-oxygenation, rendering the reliable measurement of HIF-1a a difficult task. Heat shock protein 90 (Hsp90) is an essential protein that controls the activity, turnover, and trafficking of a variety of other proteins including HIF-1a and cell cycle regulators. Hsp90 inhibitors like geldanamycin therefore have the potential to target tumor-cell survival by at least two mechanisms, compromising the accumulation of HIF-1a and cell proliferation. Methods: We describe here the simultaneous measurement of HIF-1a and cell cycle parameters by laser scanning cytometry (LSC) after exposure of two different

Similarity in the functions of HIF‑1α and HIF‑2α proteins in cervical cancer cells

“…To date, numerous cancer studies have investigated HIF-1α as an important cancer drug target (21). In cervical cancer, HIF-1α is able to affect proliferation, apoptosis, cell cycle and invasion (14,15). However, less is known about HIF-2α, another HIF-α isoform.…”

“…Although clinically relevant associations between HIF-1α expression and lymph node metastasis were not identified (12), HIF-1α was demonstrated to trigger angiogenesis and tumour invasiveness to surrounding tissues at an early stage of cervical carcinoma (13), and the inhibition of HIF-1α attenuated cell migration under normoxia and hypoxia in the uterine cervix cancer cell line SiHa (14). In addition, HIF-1α may affect proliferation, apoptosis and cell cycle (14,15). To date, there are a limited number of studies on the function of HIF-2α in cervical cancer.…”

Heat shock protein 90 is involved in regulation of hypoxia-driven proliferation of embryonic neural stem/progenitor cells

“…HSP90 could directly interact with the PAS domain of HIF-1α to make it keep stabilization (Katschinski et al 2004). Suppression of HSP90 activity by GA could induce the degradation of HIF-1α in an O 2 independent way and inhibit the angiogenesis and energy metabolism of tumors (Isaacs et al 2002;Mabjeesh et al 2002;Schwock et al 2005;Alqawi et al 2006;Lang et al 2007). …”

Prognostic significance of S-phase fractions in peritumoral invading zone analyzed by laser scanning cytometry in patients with high-grade glioma: A preliminary study

“…The laser-excited fluorescence emitted from individual fluorochromed cells on a microscope slide is rapidly measured at multiple wavelengths with high sensitivity and accuracy. LSC has a number of applications, including the measurement of circulating tumor cells, DNA damage, DNA ploidy and cell-cycle position (19)(20)(21)(22)(23)(24)(25)(26)(27). The cells for the study are selected by the operator in a manner that is similar to that for an image analysis system.…”

“…Alternatively, the entire cell population on the slide may be measured automatically using small samples, including biopsy specimens. Although flow cytometric analysis requires a large number of cells, LSC may be performed with a relatively small number (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28).…”