Quantum dots (QDs) are a new class of fluorescent labeling for biological and biomedical applications. In this study, we detected prostate stem cell antigen (PSCA) expression correlated with tumor grade and stage in human prostate cancer by QDs-based immunolabeling and conventional immunohistochemistry (IHC), and evaluated the sensitivity and stability of QDs-based immunolabeling in comparison with IHC. Our data revealed that increasing levels of PSCA expression accompanied advanced tumor grade (QDs labeling, r = 0.732, p < 0.001; IHC, r = 0.683, p < 0.001) and stage (QDs labeling, r = 0.514, p = 0.001; IHC, r = 0.432, p = 0.005), and the similar tendency was detected by the two methods. In addition, by comparison between the two methods, QDs labeling was consistent with IHC in detecting the expression of PSCA in human prostate tissue correlated with different pathological types (K = 0.845, p < 0.001). During the observation time, QDs exhibited superior stability. The intensity of QDs fluorescence remained stable for two weeks (p = 0.083) after conjugation to the PSCA protein, and nearly 93% of positive expression with their fluorescence still could be seen after four weeks.
References
[1]
Lalani, E.N.; Laniado, M.E.; Abel, P.D. Molecular and cellular biology of prostate cancer. Cancer Metastas. Rev. 1997, 16, 29–66.
[2]
Reiter, R.E.; Gu, Z.; Watabe, T.; Thomas, G.; Szigeti, K.; David, E.; Wahl, M.; Nisitani, S.; Yamashiro, J.; Le Beau, M.M.; et al. Prostate stem cell antigen: A cell surface marker overexpressed in prostate cancer. Proc. Natl. Acad. Sci. USA 1998, 95, 1735–1740.
[3]
Smith, A.M.; Duan, H.W.; Mohs, A.M.; Nie, S. Bioconjugated quantum dots for in vivo molecular and cellular imaging. Adv. Drug Deliv. Rev. 2008, 60, 1226–1240.
Smith, A.M.; Duan, H.W.; Mohs, A.M.; Nie, S. Bioconjugated quantum dots for in vivo molecular and cellular imaging. Adv. Drug. Deliv. Rev. 2008, 60, 1226–1240.
[10]
Wu, X.; Liu, H.; Liu, J.; Haley, K.N.; Treadway, J.A.; Larson, J.P.; Ge, N.; Peale, F.; Bruchez, M.P. Immunofluorescent labeling of cancer marker Her2 and other cellular targets with semiconductor quantum dots. Nat. Biotechnol. 2003, 21, 41–46.
[11]
Lidke, D.S.; Nagy, P.; Heintzmann, R.; Arndt-Jovin, D.J.; Post, J.N.; Grecco, H.E.; Jares-Erijman, E.A.; Jovin, T.M. Quantum dot ligands provide new insights into erbB/HER receptor-mediated signal transduction. Nat. Biotechnol. 2004, 22, 198–203.
[12]
Gao, X.H.; Nie, S.M. Molecular profiling of single cells and tissue specimens with quantum dots. Trends Biotechnol. 2003, 21, 371–373.
[13]
Kim, S.; Lim, Y.T.; Soltesz, E.G.; de Grand, A.M.; Lee, J.; Nakayama, A.; Parker, J.A.; Mihaljevic, T.; Laurence, R.G.; Dor, D.M.; et al. Near-infrared fluorescent type II quantum dots for sentinel lymph node mapping. Nat. Biotechnol. 2004, 22, 93–97.
[14]
Smith, A.M.; Ruan, G.; Rhyner, M.N.; Nie, S. Engineering luminescent quantum dots for in vivo molecular and cellular imaging. Ann. Biomed. Eng. 2006, 34, 3–14.
Chen, H.; Xue, J.; Zhang, Y.; Zhu, X.; Gao, J.; Yu, B. Comparison of quantum dots immunofluorescence histochemistry and conventional immunohistochemistry for the detection of caveolin-1 and PCNA in the lung cancer tissue microarray. J. Mol. Histol. 2009, 40, 261–268.
[18]
Chen, C.; Peng, J.; Xia, H.; Wu, Q.; Zeng, L.; Xu, H.; Tang, H.; Zhang, Z.; Zhu, X.; Pang, D.; Li, Y. Quantum-dot-based immunofluorescent imaging of HER2 and ER provides new insights into breast cancer heterogeneity. Nanotechnology 2010, 21, 095101.
[19]
Gleason, D.F.; Mellinger, G.T. Prediction of prognosis for prostatic adenocarcinoma by combined histological grading and clinical staging. J. Urol. 1974, 111, 58–64.
[20]
Beahrs, O.H.; Henson, D.E.; Hutter, R.V.P.; Kennedy, B.J. AJCC Manual for Staging of Cancer, 4th ed. ed.; JB Lippincott Company: Philadelphia, PA, USA, 1992; p. 181.
[21]
Zhao, Z.G.; Shen, W. Prostate stem cell antigen (PSCA) expression in human prostate cancer tissues and its potential role in prostate carcinogenesis and progression of prostate cancer. Jpn. J. Clin. Oncol. 2006, 36, 121.
