Díaz-Ayala Ramonita, López-Nieves Marjorie, Colón Berlingeri Etienne S, Cabrera Carlos R, Cunci Lisandro, González Carlos I, Escobar Pedro F
BIDEA LLC, Molecular Science Research Center, Lab 2-43, 1390 Ave. Ponce de León, San Juan 002926-2614, Puerto Rico.
Department of Chemistry and Biochemistry, University of Texas at El Paso, 500 W. University Ave., El Paso, Texas 79968, United States.
ACS Omega. 2022 Mar 9;7(11):9964-9972. doi: 10.1021/acsomega.2c00713. eCollection 2022 Mar 22.
Telomerase overexpression has been associated directly with cancer, and the enzyme itself is recognized within the scientific community as a cancer biomarker. BIDEA's biosensing strip (BBS) is an innovative technology capable of detecting the presence of telomerase activity (TA) using electrochemical impedance spectroscopy (EIS). This BBS is an interdigital gold (GID) electrode array similar in size and handling to a portable glucose sensor. For the detection of the biomarker, BBS was modified by the immobilization of a telomere-like single strand DNA (ssDNA) on its surface. The sensor was exposed to telomerase-positive extract from commercially available cancer cells, and the EIS spectra were measured. Telomerase recognizes the sequence of this immobilized ssDNA probe on the BBS, and the reverse transcription process that occurs in cancer cells is replicated, resulting in the ssDNA probe elongation. This surface process caused by the presence of TA generates changes in the capacitive process on the electrode array microchip surface, which is followed by EIS as the sensing tool and correlated with the presence of cancer cells. The telomerases' total cell extraction protocol results demonstrate significant changes in the charge-transfer resistance ( ) change rate after exposure to telomerase-positive extract with a detection limit of 2.94 × 10 cells/mL. Finally, a preliminary study with a small set of "blind" uterine biopsy samples suggests the feasibility of using the changes in the magnitude change rate (Δ(Δ / )/Δ) to distinguish positive from negative endometrial adenocarcinoma samples by the presence or absence of TA.
端粒酶的过度表达与癌症直接相关，并且该酶本身在科学界被公认为一种癌症生物标志物。BIDEA的生物传感条（BBS）是一项创新技术，能够使用电化学阻抗谱（EIS）检测端粒酶活性（TA）的存在。这种BBS是一种叉指式金（GID）电极阵列，其尺寸和操作方式与便携式葡萄糖传感器相似。为了检测生物标志物，BBS通过在其表面固定类似端粒的单链DNA（ssDNA）进行修饰。将该传感器暴露于市售癌细胞的端粒酶阳性提取物中，并测量EIS光谱。端粒酶识别BBS上这种固定化ssDNA探针的序列，并复制癌细胞中发生的逆转录过程，导致ssDNA探针延长。由TA的存在引起的这种表面过程会在电极阵列微芯片表面的电容过程中产生变化，随后以EIS作为传感工具，并与癌细胞的存在相关联。端粒酶的全细胞提取方案结果表明，在暴露于端粒酶阳性提取物后，电荷转移电阻（ ）变化率有显著变化，检测限为2.94×10个细胞/毫升。最后，对一小批“盲法”子宫活检样本的初步研究表明，利用 幅度变化率（Δ(Δ / )/Δ）的变化来通过TA的存在与否区分子宫内膜腺癌阳性和阴性样本是可行的。
