L-DOPA decarboxylase mRNA expression is associated with tumor stage and size in head and neck squamous cell carcinoma: a retrospective cohort study.
BACKGROUND
Head and neck squamous cell carcinoma (HNSCC) represents one of the most commonly diagnosed malignancies worldwide. The DDC gene encodes L-DOPA decarboxylase, an enzyme catalyzing the decarboxylation of L-DOPA to dopamine. We have recently shown that DDC mRNA is a significant predictor of patients' prognosis in colorectal adenocarcinoma and prostate cancer. The aim of the current study was to analyze the DDC mRNA expression in HNSCC patients.


METHODS
53 malignant tumors were resected from the larynx, pharynx, tongue, buccal mucosa, parotid glands, and nasal cavity, as well as from 34 adjacent non-cancerous tissues of HNSCC patients, and were homogenized. Total RNA was isolated and converted into first-strand cDNA. An ultrasensitive real-time PCR method based on the SYBR Green chemistry was used for DDC mRNA quantification in head and neck tissue specimens. Relative quantification was performed using the comparative Ct (2-ddCt) method.


RESULTS
DDC mRNA levels were lower in squamous cell carcinomas (SCCs) of the larynx and tongue than in adjacent non-cancerous tissue specimens. Furthermore, low DDC mRNA expression was noticed in laryngeal and tongue tumors of advanced TNM stage or bigger size, compared to early-stage or smaller tumors, respectively. No statistically significant differences were observed between SCCs resected from pharynx, buccal mucosa, or nasal cavity, and their normal counterparts.


CONCLUSIONS
This is the first study examining the DDC mRNA expression in HNSCC. According to our results, DDC mRNA expression may constitute a potential prognostic biomarker in tongue and/or larynx SCCs, which principally represent the overwhelming majority of HNSCC cases.
Department of Biochemistry and Molecular Biology, University of Athens, Panepistimiopolis, Athens 15701, Greece. ascorilas@biol.uoa.gr.
Panagiota-Aikaterini
PA
Geomela
Christos K
CK
Kontos
Ioannis
I
Yiotakis
Emmanuel G
EG
Fragoulis
Andreas
A
Scorilas
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D004296:Dopa Decarboxylase / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck; D018709:Statistics, Nonparametric
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D004296:Dopa Decarboxylase