Identification of novel hypoxia response genes in human glioma cell line a172

Abstract

Objective(s): Hypoxia is a serious challenge for treatment of solid tumors. This condition has been manifested to exert significant therapeutic effects on glioblastoma multiform or (WHO) astrocytoma grade IV. Hypoxia contributes numerous changes in cellular mechanisms such as angiogenesis, metastasis and apoptosis evasion. Furthermore, in molecular level, hypoxia can cause induction of DNA breaks in tumor cells. Identification of mechanisms responsible for these effects can lead to designing more efficient therapeutic strategies against tumor progression which results in improvement of patient prognosis. Materials and Methods : In order to identify more hypoxia regulated genes which may have a role in glioblastoma progression, cDNA-AFLP was optimized as a Differential display method which is able to identify and isolate transcripts with no prior sequence knowledge.

Results: Using this method, the current study identified 120 Transcription Derived Fragments (TDFs) which were completely differentially regulated in response to hypoxia. By sequence homology searching, the current study could detect 22 completely differentially regulated known genes and two unknown sequence matching with two chromosome contig and four sequence matches with some Expressed Sequence Tags (ESTs).

Conclusion: Further characterizing of these genes may help to achieve better understanding of hypoxia mediated phenotype change in tumor cells.

Keywords: Glioblastoma; Hypoxia; cDNA-AFLP.

Figure 1

Expression of Hypoxia and Normoxia transcripts displayed by cDNA-AFLP. An example showing selective amplification with three diffrent primer combination (Ms5 as forward primer and Mb 5-7 as reverse primers in A1-A3 respectively) of A172 Glioma cell line exposed to Hypoxia stress. Arrows indicate transcript-derived fragments that show differential expression in either in hypoxia (h) or normoxia condition (n). M represents 100bp molecular weight marker.