Table 1 Evidence linking hypoxia to tumor cell genetic instability

Rice et al. [70]

0%

AA8 (CHO)

Flow cytometry, gene copy analyses

- Anoxia induces S-phase overreplication and increases the frequency of dihydrofolate reductase gene amplification

Young et al. [71]

0% (<10 ppm)

KHT-C2-LP1 (M-fibrosarcoma),

Metastasis assay, flow cytometry

- Anoxia induces DNA overreplication and increases metastatic potential

B16F10-A1 (M-melanoma)

Reynolds et al. [61]

0% (<10 ppm)

LN12 (M-fibroblasts)

Chromosome based λ shuttle vector, PCR, DNA sequence analysis

- Anoxia induces 3–4 fold increase in supF tRNA suppressor gene mutation (transversions and deletions) frequency

Rofstad et al. [72]

0% (<10 ppm and <100 ppm)

BEX-c (H-melanoma),

Flow cytometry, Giemsa

- Anoxia followed by reoxygenation induces diplochromosomes and tetraploidization

SAX-c (H-melanoma)

Coquelle et al. [73]

0.02%

GMA32 (Chinese hamster fibroblasts)

Fluorescence in situ hybridization (FISH)

- Severe hypoxia induces fragile sites and generates homogeneously stained regions (HSRs)

Yuan et al. [74]

0% (<10 ppm)

3340 (M-fibroblast)

Host cell reactivation (HCR) assay, UV mutagenesis assay

- Anoxia induces 2-fold increase in supFG1 mutation frequency

Coquelle et al. [75]

0.02%

GMA32 (Chinese hamster fibroblasts), 112 (Chinese hamster fibroblasts)

Fluorescence in situ hybridization (FISH)

- Severe hypoxia activates fragile sites and generates double minutes and dicentric chromosomes

Mihaylova et al. [76]

0% <10 ppm

3340 (M-fibroblasts), HeLa (H-cervix adenocarcinoma), EMT6 (M-breast carcinoma)

β-galactosidase and supFG1 mutation assays

- Anoxia induces 2-fold increase in supFG1, cII and lacZ mutation frequency

Banath et al. [77]

i.p. pimonidazole

V79-VE (Chinese hamster fibroblasts),

Flow cytometry, γ-H2AX foci, HPRT mutation assay, alkaline comet assay

- Hypoxia (cells distant to the blood vessels) followed by reoxygenation does not alter mutation frequency at HPRT locus, DNA strand break rejoining or resolution of γ-H2AX foci following ionizing radiation (IR)

HCT116 (H-colon carcinoma),

SCCVII (M-squamous cell carcinoma)

Koshiji et al. [78]

1%

HCT116 (H-colon carcinoma),

β-galactosidase mutation assay, microsatellite analysis

- Hypoxia increases the frequency of microsatellite mutations

HEC59 (H-endometrial carcinoma)

Papp-Szabo et al. [59]

0%

ME (R-mammary epithelial cells),

cII mutagenicity assay

- Anoxia increases the mutation frequency by 2-fold at cII locus without affecting colonogenic survival

MFib (R-mammary fibroblasts)

Fischer et al. [79]

0%

TX3868 (H-glioblastoma)

Fluorescence in situ hybridization (FISH)

- Anoxia induces double minutes, fragile sites and anaphase-bridges and initiates gene amplification on chromosome 12q

Rodriguez-Jimenez et al. [80]

1%

C17.2 (M-multipotent neural precursor cells), M-primary neurospheres from CD31, BMMSC (H-mesenchymal stem cells), DPSC (H-mesenchymal stem cells)

Host cell reactivation (HCR) assay, microsatellite instability analysis

- Hypoxia increases mutation frequency of the β-galactosidase reporter gene and causes microsatellite instability

Keysar et al. [60]

<0.1%

A_L(N) (CHO)

Complement cytotoxic assay, flow cytometry mutation assay

- Anoxia results in a significant induction of mutations especially large deletions in CD59 gene

Lee et al. [81]

3%

Primary lymphocytes from healthy donors

Sister chromatid exchange (SCE) assay, microsatellite instability assay

- Hypoxia increases SCE but does not alter microsatellite instability

Pires et al. [38]

<0.02%

RKO (H-colon carcinoma), HCT116 (H-colon carcinoma), U2OS (H-osteosarcoma), IBR3 (H-fibroblast)

DNA fiber analysis, immunofluorescence

- Anoxia blocks DNA replication at the initiation and elongation stages and compromises DNA replication restart - Acute anoxia following reoxygenation (cycling hypoxia) does not affect DNA replication restart

Kumareswaran et al.* [82]

0.2%

GM05757 (H-fibroblasts)

Giemsa, Multicolor fluorescence in situ hybridization (M-FISH)

- Hypoxia increases the frequency of fragmented DNA, ring chromosomes, telomeric fusions, chromosomal translocations and marker chromosomes following exogenous DNA damage