Nicotinic cholinergic receptors in esophagus: Early alteration during carcinogenesis and prognostic value.
OBJECTIVE
To compare expression of nicotinic cholinergic receptors (CHRNs) in healthy and squamous cell carcinoma-affected esophagus and determine the prognostic value.


METHODS
We performed RT-qPCR to measure the expression of CHRNs in 44 esophageal samples from healthy individuals and in matched normal surrounding mucosa, and in tumors from 28 patients diagnosed with esophageal squamous cell carcinoma (ESCC). Next, we performed correlation analysis for the detected expression of these receptors with the habits and clinico-pathological characteristics of all study participants. In order to investigate the possible correlations between the expression of the different CHRN subunits in both healthy esophagus and tissues from ESCC patients, correlation matrices were generated. Subsequently, we evaluated whether the detected alterations in expression of the various CHRNs could precede histopathological modifications during the esophageal carcinogenic processes by using receiver operating characteristic curve analysis. Finally, we evaluated the impact of CHRNA5 and CHRNA7 expression on overall survival by using multivariate analysis.


RESULTS
CHRNA3, CHRNA5, CHRNA7 and CHRNB4, but not CHRNA1, CHRNA4, CHRNA9 or CHRNA10, were found to be expressed in normal (healthy) esophageal mucosa. In ESCC, CHRNA5 and CHRNA7 were overexpressed as compared with patient-matched surrounding non-tumor mucosa (ESCC-adjacent mucosa; P < 0.0001 and P = 0.0091, respectively). Positive correlations were observed between CHRNA3 and CHRNB4 expression in all samples analyzed. Additionally, CHRNB4 was found to be differentially expressed in the healthy esophagus and the normal-appearing ESCC-adjacent mucosa, allowing for distinguishment between these tissues with a sensitivity of 75.86% and a specificity of 78.95% (P = 0.0002). Finally, CHRNA5 expression was identified as an independent prognostic factor in ESCC; patients with high CHRNA5 expression showed an increased overall survival, in comparison with those with low expression. The corresponding age- and tumor stage-adjusted hazard ratio was 0.2684 (95%CI: 0.075-0.97, P = 0.0448).


CONCLUSIONS
Expression of CHRNs is homogeneous along healthy esophagus and deregulated in ESCC, suggesting a pathogenic role for these receptors in ESCC development and progression.
Marina Chianello Nicolau, Luis Felipe Ribeiro Pinto, Ana Rossini, Tatiana de Almeida Simão, Departamento de Bioquímica, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-013, Brazil.
Marina
M
Chianello Nicolau
Marina Chianello Nicolau, Luis Felipe Ribeiro Pinto, Ana Rossini, Tatiana de Almeida Simão, Departamento de Bioquímica, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-013, Brazil.
Luis Felipe Ribeiro
LF
Pinto
Marina Chianello Nicolau, Luis Felipe Ribeiro Pinto, Ana Rossini, Tatiana de Almeida Simão, Departamento de Bioquímica, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-013, Brazil.
Pedro
P
Nicolau-Neto
Marina Chianello Nicolau, Luis Felipe Ribeiro Pinto, Ana Rossini, Tatiana de Almeida Simão, Departamento de Bioquímica, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-013, Brazil.
Paulo Roberto Alves
PR
de Pinho
Marina Chianello Nicolau, Luis Felipe Ribeiro Pinto, Ana Rossini, Tatiana de Almeida Simão, Departamento de Bioquímica, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-013, Brazil.
Ana
A
Rossini
Marina Chianello Nicolau, Luis Felipe Ribeiro Pinto, Ana Rossini, Tatiana de Almeida Simão, Departamento de Bioquímica, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-013, Brazil.
Tatiana
T
de Almeida Simão
Marina Chianello Nicolau, Luis Felipe Ribeiro Pinto, Ana Rossini, Tatiana de Almeida Simão, Departamento de Bioquímica, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-013, Brazil.
Sheila Coelho
SC
Soares Lima
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000401:mortality; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000401:mortality; D000077277:Esophageal Squamous Cell Carcinoma; D004947:Esophagus / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis; D011978:Receptors, Nicotinic / Q000032:analysis* / Q000235:genetics
D012333:RNA, Messenger; D011978:Receptors, Nicotinic
Alcohol; Esophageal squamous cell carcinoma; Esophagus; Gene expression; Nicotinic cholinergic receptors; Tobacco