Gene expression of somatostatin receptor subtypes SSTR2a, SSTR3 and SSTR5 in peripheral blood of neuroendocrine lung cancer affected patients

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Background Somatostatin (SS) acts as a universal endocrine off-switch, and also inhibits the growth of neuroendocrine tumours through its specific receptors (SSTRs). Somatostatin receptors are G-protein-coupled receptors, which are encoded by five separate genes (SSTR1-5). Short peptide analogues demonstrate specific binding only for the subgroup consisting of SSTR2a, SSTR3 and SSTR5. Moreover, previous studies reported that expression of mRNA for SSTR2a correlated with therapeutic outcome in patients with carcinoid tumours treated with somatostatin analogs. Purpose To develop and apply a Real Time Quantitative PCR technique (RT-qPCR) to compare and contrast the mRNA levels of SSTR2a, SSTR3 and SSTR5 in Neuroendocrine Lung Cancer affected patients. Methods Peripheral blood samples from 21 neuroendocrine lung cancer affected patients (14 SCLC, 6 LC and 1LCNEC) subjected to scintigraphy with 111In-DTPA-DPhe1- octreotide (OctreoScan) and 24 healthy blood donors were investigated by RT-qPCR. mRNA levels for SSTR2a, SSTR3 and SSTR5 were measured in peripheral blood samples with a relative quantification method using plasmid dilutions as calibration curves and GAPDH as reference gene. Results A statistically significant increase in target genes/ GAPDH copy number ratio was found for SSTR2a (median 38; IQR 22-141) and SSTR5 (median 51; IQR 19-499) in neuroendocrine lung cancer affected patients as compared with samples from healthy blood donors (P≤0.0003 and P≤0.0005). Since low levels of expression were detected in the control group for all three genes, optimal cut-off values were assessed using ROC curve analyses and were equal to 9.05 for SSTR2a and 16.97 for SSTR5. These cut off values resulted in a sensitivity of 86% (95%IC 65-95) for both markers and a specificity of 83% (95%IC 64-93%) and 79% (95%IC 60-91%) for SSTR2a and SSTR5 respectively. Comparison between OctreoScan results and RT-qPCR analysis demonstrated agreement in 76% of the cases. Conclusions Our results suggest that SSTR2a and SSTR5 mRNAs are detectable in peripheral blood of neuroendocrine lung cancer affected patients using real-time quantitative PCR, with a good agreement with OctreoScan. The high sensitivity of this non-invasive molecular technique suggests that this method could represent a useful tool in the clinical management of neuroendocrine lung cancers.

Original languageEnglish
Pages (from-to)435-441
Number of pages7
JournalCellular Oncology
Volume34
Issue number5
DOIs
Publication statusPublished - Oct 2011

Fingerprint

Somatostatin Receptors
Lung Neoplasms
Real-Time Polymerase Chain Reaction
Gene Expression
Messenger RNA
Somatostatin
Blood Donors
ROC Curve
Genes
Pentetic Acid
Octreotide
Gene Dosage
Neuroendocrine Tumors
Carcinoid Tumor
G-Protein-Coupled Receptors
Radionuclide Imaging
Calibration
Plasmids
Control Groups
Peptides

Keywords

  • Neuroendocrine lung cancer
  • Real-time quantitative PCR
  • SSTRs

ASJC Scopus subject areas

  • Cancer Research
  • Molecular Medicine
  • Oncology
  • Medicine(all)

Cite this

@article{ad68b96207154f2793c96a98742e3c6f,
title = "Gene expression of somatostatin receptor subtypes SSTR2a, SSTR3 and SSTR5 in peripheral blood of neuroendocrine lung cancer affected patients",
abstract = "Background Somatostatin (SS) acts as a universal endocrine off-switch, and also inhibits the growth of neuroendocrine tumours through its specific receptors (SSTRs). Somatostatin receptors are G-protein-coupled receptors, which are encoded by five separate genes (SSTR1-5). Short peptide analogues demonstrate specific binding only for the subgroup consisting of SSTR2a, SSTR3 and SSTR5. Moreover, previous studies reported that expression of mRNA for SSTR2a correlated with therapeutic outcome in patients with carcinoid tumours treated with somatostatin analogs. Purpose To develop and apply a Real Time Quantitative PCR technique (RT-qPCR) to compare and contrast the mRNA levels of SSTR2a, SSTR3 and SSTR5 in Neuroendocrine Lung Cancer affected patients. Methods Peripheral blood samples from 21 neuroendocrine lung cancer affected patients (14 SCLC, 6 LC and 1LCNEC) subjected to scintigraphy with 111In-DTPA-DPhe1- octreotide (OctreoScan) and 24 healthy blood donors were investigated by RT-qPCR. mRNA levels for SSTR2a, SSTR3 and SSTR5 were measured in peripheral blood samples with a relative quantification method using plasmid dilutions as calibration curves and GAPDH as reference gene. Results A statistically significant increase in target genes/ GAPDH copy number ratio was found for SSTR2a (median 38; IQR 22-141) and SSTR5 (median 51; IQR 19-499) in neuroendocrine lung cancer affected patients as compared with samples from healthy blood donors (P≤0.0003 and P≤0.0005). Since low levels of expression were detected in the control group for all three genes, optimal cut-off values were assessed using ROC curve analyses and were equal to 9.05 for SSTR2a and 16.97 for SSTR5. These cut off values resulted in a sensitivity of 86{\%} (95{\%}IC 65-95) for both markers and a specificity of 83{\%} (95{\%}IC 64-93{\%}) and 79{\%} (95{\%}IC 60-91{\%}) for SSTR2a and SSTR5 respectively. Comparison between OctreoScan results and RT-qPCR analysis demonstrated agreement in 76{\%} of the cases. Conclusions Our results suggest that SSTR2a and SSTR5 mRNAs are detectable in peripheral blood of neuroendocrine lung cancer affected patients using real-time quantitative PCR, with a good agreement with OctreoScan. The high sensitivity of this non-invasive molecular technique suggests that this method could represent a useful tool in the clinical management of neuroendocrine lung cancers.",
keywords = "Neuroendocrine lung cancer, Real-time quantitative PCR, SSTRs",
author = "Muscarella, {Lucia Anna} and Vito D'Alessandro and Torre, {Annamaria La} and Massimiliano Copetti and {De Cata}, Angelo and Paola Parrella and Marco Sperandeo and Fabio Pellegrini and Vincenzo Frusciante and Evaristo Maiello and Giuseppe Merla and Fazio, {Vito Michele} and Gianluigi Vendemiale",
year = "2011",
month = "10",
doi = "10.1007/s13402-011-0025-9",
language = "English",
volume = "34",
pages = "435--441",
journal = "Cellular oncology (Dordrecht)",
issn = "2211-3428",
publisher = "IOS Press",
number = "5",

}

TY - JOUR

T1 - Gene expression of somatostatin receptor subtypes SSTR2a, SSTR3 and SSTR5 in peripheral blood of neuroendocrine lung cancer affected patients

AU - Muscarella, Lucia Anna

AU - D'Alessandro, Vito

AU - Torre, Annamaria La

AU - Copetti, Massimiliano

AU - De Cata, Angelo

AU - Parrella, Paola

AU - Sperandeo, Marco

AU - Pellegrini, Fabio

AU - Frusciante, Vincenzo

AU - Maiello, Evaristo

AU - Merla, Giuseppe

AU - Fazio, Vito Michele

AU - Vendemiale, Gianluigi

PY - 2011/10

Y1 - 2011/10

N2 - Background Somatostatin (SS) acts as a universal endocrine off-switch, and also inhibits the growth of neuroendocrine tumours through its specific receptors (SSTRs). Somatostatin receptors are G-protein-coupled receptors, which are encoded by five separate genes (SSTR1-5). Short peptide analogues demonstrate specific binding only for the subgroup consisting of SSTR2a, SSTR3 and SSTR5. Moreover, previous studies reported that expression of mRNA for SSTR2a correlated with therapeutic outcome in patients with carcinoid tumours treated with somatostatin analogs. Purpose To develop and apply a Real Time Quantitative PCR technique (RT-qPCR) to compare and contrast the mRNA levels of SSTR2a, SSTR3 and SSTR5 in Neuroendocrine Lung Cancer affected patients. Methods Peripheral blood samples from 21 neuroendocrine lung cancer affected patients (14 SCLC, 6 LC and 1LCNEC) subjected to scintigraphy with 111In-DTPA-DPhe1- octreotide (OctreoScan) and 24 healthy blood donors were investigated by RT-qPCR. mRNA levels for SSTR2a, SSTR3 and SSTR5 were measured in peripheral blood samples with a relative quantification method using plasmid dilutions as calibration curves and GAPDH as reference gene. Results A statistically significant increase in target genes/ GAPDH copy number ratio was found for SSTR2a (median 38; IQR 22-141) and SSTR5 (median 51; IQR 19-499) in neuroendocrine lung cancer affected patients as compared with samples from healthy blood donors (P≤0.0003 and P≤0.0005). Since low levels of expression were detected in the control group for all three genes, optimal cut-off values were assessed using ROC curve analyses and were equal to 9.05 for SSTR2a and 16.97 for SSTR5. These cut off values resulted in a sensitivity of 86% (95%IC 65-95) for both markers and a specificity of 83% (95%IC 64-93%) and 79% (95%IC 60-91%) for SSTR2a and SSTR5 respectively. Comparison between OctreoScan results and RT-qPCR analysis demonstrated agreement in 76% of the cases. Conclusions Our results suggest that SSTR2a and SSTR5 mRNAs are detectable in peripheral blood of neuroendocrine lung cancer affected patients using real-time quantitative PCR, with a good agreement with OctreoScan. The high sensitivity of this non-invasive molecular technique suggests that this method could represent a useful tool in the clinical management of neuroendocrine lung cancers.

AB - Background Somatostatin (SS) acts as a universal endocrine off-switch, and also inhibits the growth of neuroendocrine tumours through its specific receptors (SSTRs). Somatostatin receptors are G-protein-coupled receptors, which are encoded by five separate genes (SSTR1-5). Short peptide analogues demonstrate specific binding only for the subgroup consisting of SSTR2a, SSTR3 and SSTR5. Moreover, previous studies reported that expression of mRNA for SSTR2a correlated with therapeutic outcome in patients with carcinoid tumours treated with somatostatin analogs. Purpose To develop and apply a Real Time Quantitative PCR technique (RT-qPCR) to compare and contrast the mRNA levels of SSTR2a, SSTR3 and SSTR5 in Neuroendocrine Lung Cancer affected patients. Methods Peripheral blood samples from 21 neuroendocrine lung cancer affected patients (14 SCLC, 6 LC and 1LCNEC) subjected to scintigraphy with 111In-DTPA-DPhe1- octreotide (OctreoScan) and 24 healthy blood donors were investigated by RT-qPCR. mRNA levels for SSTR2a, SSTR3 and SSTR5 were measured in peripheral blood samples with a relative quantification method using plasmid dilutions as calibration curves and GAPDH as reference gene. Results A statistically significant increase in target genes/ GAPDH copy number ratio was found for SSTR2a (median 38; IQR 22-141) and SSTR5 (median 51; IQR 19-499) in neuroendocrine lung cancer affected patients as compared with samples from healthy blood donors (P≤0.0003 and P≤0.0005). Since low levels of expression were detected in the control group for all three genes, optimal cut-off values were assessed using ROC curve analyses and were equal to 9.05 for SSTR2a and 16.97 for SSTR5. These cut off values resulted in a sensitivity of 86% (95%IC 65-95) for both markers and a specificity of 83% (95%IC 64-93%) and 79% (95%IC 60-91%) for SSTR2a and SSTR5 respectively. Comparison between OctreoScan results and RT-qPCR analysis demonstrated agreement in 76% of the cases. Conclusions Our results suggest that SSTR2a and SSTR5 mRNAs are detectable in peripheral blood of neuroendocrine lung cancer affected patients using real-time quantitative PCR, with a good agreement with OctreoScan. The high sensitivity of this non-invasive molecular technique suggests that this method could represent a useful tool in the clinical management of neuroendocrine lung cancers.

KW - Neuroendocrine lung cancer

KW - Real-time quantitative PCR

KW - SSTRs

UR - http://www.scopus.com/inward/record.url?scp=84860570657&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84860570657&partnerID=8YFLogxK

U2 - 10.1007/s13402-011-0025-9

DO - 10.1007/s13402-011-0025-9

M3 - Article

VL - 34

SP - 435

EP - 441

JO - Cellular oncology (Dordrecht)

JF - Cellular oncology (Dordrecht)

SN - 2211-3428

IS - 5

ER -