Cancer Science & Therapy

Assessment of the Expression of Long Noncoding Mitochondrial RNAs (lncmtRNAs) During Cervical Cancer Progression and Cervical Carcinoma

Abstract

Komal Dadlani, Constanza Lopez, Fernando Gabler, Juan Carlos Roa, Claudio Villota, Luisa Lina-Villa, Enrique Boccardo, Eva Bustamante, Veronica Burzio, Luis O. Burzio and Jaime Villegas Olavarria

Objective: Cervical cancer is the second most common cancer in women with high rates of mortality worldwide. Cervical cancer is slowly progressive and is preceded by pre-invasive intraepithelial lesions. Therefore, detection of premalignant lesions is key to preventing disease progression to advanced stages. The objective of the present study was examination and quantification of the differentially expressed non-coding mitochondrial RNAs during progression of disease.
Material and methods: The differential expression of S-ncmtRNA and AS-ncmtRNA was analyzed by in situ hybridization (ISH) using tissue macroarrays (TMA) from normal, CIN1, CIN2, CIN3 and invasive squamous carcinoma (SCC). PCNA and p16INK-4a were detected in consecutive biopsies by immunohistochemistry. Quantification of ISH signal was carried out with Image ProPlus 6.1 software and the results were expressed as percentage of Integrated Optical Density (IOD).
Results: We found a marked down-regulation of AS-ncmtRNA in 95% of tissues analyzed (CIN 1/2, CIN 3, and invasive squamous cancer). Moreover, differential expression of ASncmtRNA v/s S-ncmtRNA showed significant difference. Normal proliferating tissues did not display down-regulation of AS-ncmtRNA. Down regulation of ASncmtRNA correlated with the expression of the tumor suppressor protein p16INK-4a Conclusions: We found down-regulation of AS-ncmtRNA in pre-malignant and tumor samples which could distinguish normal tissues from early lesions and tumor samples. These results suggest that the down-regulation of AS-ncmtRNA is a novel marker of early lesions and cervix neoplasia.