14 Perspectives of Aptamers for Medical Applications
427
used the carboxyfluorescein—(FAM) labeled CA 125 aptamer and the fluorescence
quenching method to identify CA 125. The detection limit is found as 0.05 U/mL.
In another research, authors [131] using gold nanoparticles (AuNPs) to enhance the
hybridization chain reaction (HCR). This method improves the sensitivity of electrochemical immunoassay for the detection of CA125, which presents a potential
in clinical application after it was successfully applied to detect CA125 in human
serum samples. Its detection limit is 50 μU.mL
−1 . To further enhance the sensitivity,
Hamd-Ghadareh et al. [132] developed an ultrasensitive sandwich-type antibodyssDNA aptamer fluorescence immunosensor for CA125 detection. The sandwichtype assay was fulfilled with the carbon dots (CDs) functionalized with aptamer (CDaptamer) used as detection probe and PAMAM-Dendrimers/AuNPs used for covalent attachment of CA125-antibody. Under optimal conditions, the aptamer-based
immunosensor exhibited an extremely low calculated detection limit of 0.5 fg/mL
with a wide linear range of 1.0 fg/mL–1.0 ng/mL of CA 125. The aptasensor was
also applied for CA125 detection in serum samples and measuring of ovarian cancer
cells with a detection limit of 400 cells/mL (4 cells in 10 μL), indicating the potential
application of aptasensorin clinical monitoring of tumor biomarkers.
Human papillomavirus (HPVs) related aptamer is another important and
promising biomarker, especially in the detection of cervical cancer. HPVs are nonenveloped DNA viruses, it is the most common viral infection of the reproductive tract,
affecting both men and women. High-risk HPVs, particularly HPV type 16 (HPV-16),
are known to act as oncogenes that promote tumor growth and malignant transformation [133], Most notably, HPV-16 E7 is a potential biomarker and therapy target, it
interacts with the tumor suppressor protein pRb, promoting its degradation, leading
to cell cycle dysregulation in infected cells. Nicol et al. [96] synthesized an RNA
aptamer against HPV-16E7 oncoprotein. Another aptamer specific to the tyrosine
kinase-7 human protein is generally expressed in cervical cancer. Trausch et al. [45]
constructed a slow off-rate modified DNA aptamer (SOMAmer), termed HPV-07,
to bind the Type 16 virus-like-particle (VLP) formed by the self-assembling capsid
protein L1. It has specificity for VLP, with high binding sensitivity (EC50 of 0.1–
0.4 μg/mL depending on assay form). This enables HPV-07 to be suitable reagents
for biological potency assays.
14.4 Aptamers Application in Disease
14.4.1 Tumor
14.4.1.1 Hematological Malignancies
Precision medicine has recently emerged as a promising strategy for cancer therapy
because it not only specifically targets cancer cells, but also does not have adverse
effects on normal cells. Aptamers have great potential in precision cancer therapy
427
used the carboxyfluorescein—(FAM) labeled CA 125 aptamer and the fluorescence
quenching method to identify CA 125. The detection limit is found as 0.05 U/mL.
In another research, authors [131] using gold nanoparticles (AuNPs) to enhance the
hybridization chain reaction (HCR). This method improves the sensitivity of electrochemical immunoassay for the detection of CA125, which presents a potential
in clinical application after it was successfully applied to detect CA125 in human
serum samples. Its detection limit is 50 μU.mL
−1 . To further enhance the sensitivity,
Hamd-Ghadareh et al. [132] developed an ultrasensitive sandwich-type antibodyssDNA aptamer fluorescence immunosensor for CA125 detection. The sandwichtype assay was fulfilled with the carbon dots (CDs) functionalized with aptamer (CDaptamer) used as detection probe and PAMAM-Dendrimers/AuNPs used for covalent attachment of CA125-antibody. Under optimal conditions, the aptamer-based
immunosensor exhibited an extremely low calculated detection limit of 0.5 fg/mL
with a wide linear range of 1.0 fg/mL–1.0 ng/mL of CA 125. The aptasensor was
also applied for CA125 detection in serum samples and measuring of ovarian cancer
cells with a detection limit of 400 cells/mL (4 cells in 10 μL), indicating the potential
application of aptasensorin clinical monitoring of tumor biomarkers.
Human papillomavirus (HPVs) related aptamer is another important and
promising biomarker, especially in the detection of cervical cancer. HPVs are nonenveloped DNA viruses, it is the most common viral infection of the reproductive tract,
affecting both men and women. High-risk HPVs, particularly HPV type 16 (HPV-16),
are known to act as oncogenes that promote tumor growth and malignant transformation [133], Most notably, HPV-16 E7 is a potential biomarker and therapy target, it
interacts with the tumor suppressor protein pRb, promoting its degradation, leading
to cell cycle dysregulation in infected cells. Nicol et al. [96] synthesized an RNA
aptamer against HPV-16E7 oncoprotein. Another aptamer specific to the tyrosine
kinase-7 human protein is generally expressed in cervical cancer. Trausch et al. [45]
constructed a slow off-rate modified DNA aptamer (SOMAmer), termed HPV-07,
to bind the Type 16 virus-like-particle (VLP) formed by the self-assembling capsid
protein L1. It has specificity for VLP, with high binding sensitivity (EC50 of 0.1–
0.4 μg/mL depending on assay form). This enables HPV-07 to be suitable reagents
for biological potency assays.
14.4 Aptamers Application in Disease
14.4.1 Tumor
14.4.1.1 Hematological Malignancies
Precision medicine has recently emerged as a promising strategy for cancer therapy
because it not only specifically targets cancer cells, but also does not have adverse
effects on normal cells. Aptamers have great potential in precision cancer therapy