RESUMEN
Aptamers are a class of molecular recognition elements that exhibit high binding affinity and specificity against their respective targets. In view of the many advantages aptamers harbor over their counterpart antibodies, we were impelled to isolate an RNA aptamer against progesterone receptor, particularly its DNA binding domain. A total of eight SELEX cycles were executed against the recombinant Progesterone Receptor DNA-binding domain (PR DBD). The RNA-protein complex in the gel shift assay was subjected to crush and soak method to elute the binders prior to conventional sequencing, the step of which was based upon to coin the term CRUSOAK-SELEX. The sequencing revealed three different classes of sequences, with one class termed, PRapt-3, showing the strongest binding against PR DBD. The dissociation constant of PRapt-3 RNA aptamer was estimated at 380 nM ± 35 nM. PRapt-3 was successfully used to develop aptamer-based diagnostic assays such as ELASA, aptamer-based dot blot, and aptamer-based western blot. The prominent highlight is the performance of the aptamer in aptacytostaining, which was unachievable with antibodies. Compared to its counterpart antibodies, PRapt-3 has a better penetration capacity in aptahistostaining using the formalin-fixed paraffin-embedded (FFPE) breast cancer cells and tissue blocks. This study represents the first ever demonstration of an aptamer against progesterone receptor and its diagnostic capacity.
Asunto(s)
Aptámeros de Nucleótidos , Receptores de Progesterona , Técnica SELEX de Producción de Aptámeros , Aptámeros de Nucleótidos/química , Receptores de Progesterona/metabolismo , Humanos , Técnica SELEX de Producción de Aptámeros/métodos , FemeninoRESUMEN
BACKGROUND: The pharmacological actions of Curcuma aromatica (wild turmeric) such as anti-inflammatory, antitumor, antifungal, antimicrobial and wound healing have been recognized since ages. However, its role as a natural histological stain has not been explored till date. AIM: To evaluate the efficacy of natural substance-Kumkum prepared from the extract of C. aromatica and slaked lime in staining the biopsied oral tissues. MATERIALS AND METHODS: A cohort study that used 60 formalin fixed paraffin embedded soft and hard tissue specimens from institutional archives were subjected to sectioning and stained using Kumkum and hematoxylin and eosin (H and E). The slides were evaluated for their staining efficacy and results were statistically analyzed using Wilcoxon signed-rank test and Independent 't' test. RESULTS: The mean of the overall parameters assessed for staining efficacy did not show statistically significant difference between the study groups in normal and pathological specimens for tooth (P = 0.410 and 0.484), bone (P = 0.133 and 0.157) and soft tissues (P = 0.186 and 0.113), respectively. This suggests that Kumkum staining efficacy is equivalent to that of routine H and E for oral tissues. Structures such as dentinoenamel junction, dentinal tubules, incremental lines of cementum, reversal and resting lines, osteocytic canaliculi, mature and immature bone could be appreciated better in Kumkum stained slides, thereby rendering a special staining property to Kumkum stain. CONCLUSION: To our knowledge, this study is the first of its kind to have used Kumkum stain obtained from C. aromatica for the differentiation of the components of tooth, bone and soft tissue structures in histostaining of oral tissues. The naturally prepared Kumkum stain possesses dual staining property both in routine and differential staining. This facilitates diagnosis of fibro-osseous lesions, bony, collagen and muscular pathologies. The natural stain also finds application in forensic odontology for age estimation.