Table II.
Study, author (ref) | Year | Collected samples | Tissue examined | n | Control | n | let-7 | Expression | Age, yearsa |
---|---|---|---|---|---|---|---|---|---|
Chang et al (22) | 2008 | Primary tumors | HNSCC | 4 | Healthy tissue (UPPP patients) | 4 | let-7i | Upregulated | 54 |
Tran et al (23) | 2010 | Cell lines | HNSCC | 9 | NA | let-7a | Upregulated | NA | |
let-7b | Upregulated | ||||||||
let-7c | Upregulated | ||||||||
let-7d | Upregulated | ||||||||
let-7f | Upregulated | ||||||||
Cui et al (28) | 2014 | NA | OCSCC | 17 | Healthy controls | 3 | let-7a | Upregulated | NA |
let-7f | Upregulated | ||||||||
Christensen et al (46) | 2009 | Whole blood and buccal cells | OCSCC | 10 | Pharyngeal cancer | 4 | let-7a | Downregulated | NA |
let-7c | Downregulated | ||||||||
let-7d | Downregulated | ||||||||
let-7f | Downregulated | ||||||||
Hui et al (40) | 2013 | FFPE | Oropharyngeal SCC | 88 | Tonsillectomy | 7 | let-7f | Upregulated | 55±11 |
let-7g | Upregulated | ||||||||
Ricieri Brito et al (41) | 2010 | Primary tumors and whole blood | OCSCC | 20 | Self-control-healthy tissue | let-7a | Downregulated (n=18) | 57 (37–90) | |
let-7a | Upregulated (n=13) | ||||||||
Chang et al (42) | 2011 | Cell lines | OCSCC | NA | Human normal keratinocyte cells | NA | let-7d | Downregulated | NA |
Maclellan et al (43) | 2012 | Serum samples | CIS+OCSCC | 30 | Non-cancer patients serum | 26 | let-7a | Upregulated | 50–93 |
let-7b | Upregulated | ||||||||
let7-d | Downregulated | ||||||||
Jakymiw et al (44) | 2010 | Cell lines | HNSCC | 6 | Healthy gingival cells | NA | let-7b | Downregulated | NA |
Yu et al (45) | 2011 | Primary tumors | Head and neck cancer metastases | 107 | Self-control-healthy tissue | let-7a | Downregulated | NA | |
50 | No metastases | 57 | let-7a | Downregulated | |||||
Current study | 2015 | Primary tumors | OCSCC | 12 | Self-control-healthy tissue | 12 | let-7f | Upregulated | 15–30 |
let-7e | Upregulated | ||||||||
Aggressive | 5 | Non aggressive | 7 | let-7c | Upregulated | ||||
OCSCC | OCSCC | let-7d | Upregulated |
All ages are ranges, with the exception of Hui et al, which is the mean age. CIS, carcinoma in situ; FFPE, formalin-fixed paraffin-embedded; HNSCC, head and neck squamous cell carcinoma; NA, not available; OCSCC, oral cavity squamous cell carcinoma; SCC, squamous cell carcinoma; UPPP, uvulopalatopharyngoplasty.